tag:theconversation.com,2011:/global/topics/glycemic-index-7631/articlesGlycemic index – The Conversation2021-12-27T12:58:46Ztag:theconversation.com,2011:article/1569002021-12-27T12:58:46Z2021-12-27T12:58:46ZNot all calories are equal – a dietitian explains the different ways the kinds of foods you eat matter to your body<figure><img src="https://images.theconversation.com/files/438740/original/file-20211221-27-qlzv07.jpg?ixlib=rb-1.1.0&rect=0%2C405%2C4431%2C3320&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Even if two foods share the same calorie count, there can be major differences in how they affect your body.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/healthy-and-unhealthy-food-background-from-fruits-royalty-free-image/1249589196">Julia_Sudnitskaya/iStock via Getty Images</a></span></figcaption></figure><p>A calorie is a calorie is a calorie, at least from a thermodynamic standpoint. It’s defined as the amount of energy needed to raise the temperature of 1 kilogram of water by 1 degree Celsius (2.2 pounds by 1.8 degrees Fahrenheit).</p>
<p>But when it comes to health and your body’s energy balance, not all calories are equal.</p>
<p>For example, <a href="https://doi.org/10.1056/NEJMoa022207">some studies have reported</a> that <a href="https://doi.org/10.1186/1743-7075-11-53">diets that are</a> <a href="https://doi.org/10.1038/sj.ijo.0800867">high-protein</a>, <a href="https://doi.org/10.1210/jc.2002-021480">low-carbohydrate</a> or a combination of the two do <a href="https://doi.org/10.1056/NEJMoa022637">yield greater weight loss</a> than diets with other levels of fat, protein and carbs.</p>
<p>If every calorie in food were the same, you wouldn’t expect to see weight-loss differences among people who eat the same number of calories that are doled out in different types of food.</p>
<p><a href="https://scholar.google.com/citations?user=nrjfStkAAAAJ&hl=en&oi=ao">Dietitians like me</a> know there are many factors that influence what a calorie means for your body. Here’s what we understand about calories and nutrition so far.</p>
<h2>Energy actually available to your body</h2>
<p>In the late 1800s, chemist W.O. Atwater and his colleagues devised a system to figure out how much energy – that is, how many calories – various foods contain. Basically, he burned up food samples and recorded how much energy they released in the form of heat.</p>
<p>Not every bit of energy in food that can combust in the lab is actually available to your body, though. What scientists call <a href="https://doi.org/10.1093/jn/124.suppl_9.1738S">metabolizable energy</a> is the difference between the total energy of the food consumed and the energy that passes out of your body, undigested, in feces and urine. For each of the three macronutrients – proteins, carbohydrates and fats – Atwater devised a percentage of the calories they contained that would actually be metabolizable.</p>
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<p>According to the Atwater system, one gram of each macronutrient is estimated to provide a certain number of calories. The U.S. Department of Agriculture still uses these calculations today to come up with an <a href="https://fdc.nal.usda.gov/">official calorie number</a> for every food.</p>
<h2>How much energy you use</h2>
<p>What you eat can affect what scientists call your body’s <a href="https://doi.org/10.1007/978-1-4419-1005-9_454">energy expenditure</a>. That’s how much energy it takes to keep you alive – energy you use breathing, digesting, keeping your blood flowing and so on – along with what you exert moving your body. You might have heard this <a href="https://theconversation.com/whether-slow-or-fast-heres-how-your-metabolism-influences-how-many-calories-you-burn-each-day-149231">referred to as metabolism</a>.</p>
<p>Diet quality can alter the body’s energy expenditure, which is also called the <a href="https://doi.org/10.1172/JCI112913">thermic effect of food</a>. For example, in one study, people eating the same number of calories per day but on either a low-carbohydrate diet or a low-fat diet had <a href="https://doi.org/10.1001/jama.2012.6607">differences in total energy expenditure</a> of about 300 calories per day. Those eating very low-carb diets used the most energy, while those eating low-fat diets used the least.</p>
<p>In another study, <a href="https://doi.org/10.1002/j.1550-8528.1994.tb00074.x">high-fat diets led to lower</a> total energy expenditure than high-carb diets did. Other researchers reported that although substituting carbs for fat did not alter energy expenditure, people who increased their protein intake to 30%-35% of their diet <a href="https://doi.org/10.1093/ajcn/79.5.899S">used more energy</a>.</p>
<p>In general, diets high in carbohydrates, <a href="https://doi.org/10.1038/sj.ijo.0800810">fat or both produce a 4%-8% increase</a> in energy expenditure, while meals <a href="https://doi.org/10.1038/sj.ejcn.1600578">high in protein cause an 11%-14% increase</a> above the resting metabolic rate. Protein has a higher thermic effect because it’s harder for the body to break down. Although these variations aren’t huge, they could <a href="https://doi.org/10.17925/EE.2013.09.02.111">contribute to the obesity epidemic</a> by encouraging a subtle average weight gain.</p>
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<a href="https://images.theconversation.com/files/438736/original/file-20211221-25-1qkrnq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Nutrition Facts panels from multiple food packages" src="https://images.theconversation.com/files/438736/original/file-20211221-25-1qkrnq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/438736/original/file-20211221-25-1qkrnq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/438736/original/file-20211221-25-1qkrnq3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/438736/original/file-20211221-25-1qkrnq3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/438736/original/file-20211221-25-1qkrnq3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/438736/original/file-20211221-25-1qkrnq3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/438736/original/file-20211221-25-1qkrnq3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Nutrition Facts food labels contain much more than just calorie counts – for good reason.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/nutrition-label-giving-information-on-good-food-royalty-free-image/185262405">Imagesbybarbara/E+ via Getty Images</a></span>
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<h2>Quality of the calories you eat</h2>
<p>Dietitians pay attention to a <a href="https://doi.org/10.1001/jama.287.18.2414">food’s glycemic index</a> and <a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/glycemic-load">glycemic load</a> – that is, how quickly and how much it will increase your blood glucose levels. A rise in blood glucose triggers the release of insulin, which in turn influences energy metabolism and storage of excess energy as fat.</p>
<p>Foods like white rice, cakes, cookies and chips are all high on the glycemic index/load. Green vegetables, raw peppers, mushrooms and legumes are all low on the glycemic index/load. There is some evidence to suggest that foods <a href="https://doi.org/10.1016/j.numecd.2013.04.008">lower on the glycemic index/load</a> may be <a href="https://doi.org/10.1001/jama.287.18.2414">better for keeping blood sugar levels regulated</a> – regardless of the calories they contain.</p>
<p>Reward centers in the brain light up when people eat high glycemic index/load foods, highlighting the <a href="https://doi.org/10.3945/ajcn.113.064113">pleasurable and addictive effect</a> of foods like candy or white breads.</p>
<p><a href="https://doi.org/10.1371/journal.pmed.1003053">The fiber content of food</a> is another thing to consider. Your body can’t digest fiber – found in plant foods like fruits, vegetables, whole grains and beans – for energy. So foods high in fiber tend to have <a href="https://doi.org/10.3945/ajcn.117.163246">less metabolizable energy</a> and can help you feel full on fewer calories.</p>
<p>Empty calories – those from foods with minimal or no nutritional value – are another factor to consider. Things like white sugar, soft drinks and many ultra-processed snacks don’t provide much, if any, benefit in the form of protein, vitamins or minerals along with their calories. The opposite would be <a href="https://www.cancer.gov/publications/dictionaries/cancer-terms/def/nutrient-dense-food">nutrient-dense foods</a> that are high in nutrients or fiber, while still being relatively low in calories. Examples are spinach, apples and beans.</p>
<p>And don’t think of empty calories as neutral. Nutritionists consider them harmful calories because they can have a negative effect on health. <a href="https://doi.org/10.1056/NEJMoa1014296">Foods that are the biggest contributors to weight gain</a> are potato chips, potatoes, sugar-sweetened beverages and meats, both processed and unprocessed. On the other hand, foods that are inversely associated with weight gain are vegetables, whole grains, fruits, nuts and yogurt.</p>
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<a href="https://images.theconversation.com/files/438737/original/file-20211221-27-1rjoeti.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="view from above of plates on a table where people are eating" src="https://images.theconversation.com/files/438737/original/file-20211221-27-1rjoeti.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/438737/original/file-20211221-27-1rjoeti.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/438737/original/file-20211221-27-1rjoeti.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/438737/original/file-20211221-27-1rjoeti.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/438737/original/file-20211221-27-1rjoeti.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/438737/original/file-20211221-27-1rjoeti.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/438737/original/file-20211221-27-1rjoeti.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Food provides more than calories.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/friends-eating-together-royalty-free-image/658616918">Ridofranz/iStock via Getty Images</a></span>
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<h2>More to health than calories and weight</h2>
<p>It is indisputable that for weight loss, the difference between the number of calories consumed and the number of calories exerted through exercise is the most important factor. But don’t fool yourself. While weight plays a role in health and longevity, weight loss alone doesn’t equate to health.</p>
<p>Yes, some high-protein diets seem to promote weight loss at least in the short term. But epidemiologists know that in areas where people live the longest – close to 100 years on average – they <a href="https://doi.org/10.1093/jn/131.11.3065S">eat a primarily plant-based diet</a>, with very low or no animal-based protein and low or moderate fat in the form of mono- and polyunsaturated fats.</p>
<p>I often hear friends or clients say things like “it’s those carbs that are making me fat” or “I need to go on a low-carb diet.” But these complaints drive dietitians like me, well, nuts. Carbohydrates include foods like Coca-Cola and candy canes, but also apples and spinach. Cutting down on simple carbs like soft drinks, refined-flour bakery items, pasta and sweets will definitely have a positive impact on health. But eliminating carbohydrates like vegetables and fruit will have the opposite effect.</p>
<p><a href="https://doi.org/10.1016/j.ebiom.2019.04.005">A plant-based diet</a> <a href="https://doi.org/10.1136/bmj.m2412">high in plant-based protein</a> <a href="https://doi.org/10.1016/j.cell.2015.02.020">and carbohydrates</a> mostly from vegetables, fruit, nuts and legumes is <a href="https://doi.org/10.1079/phn2004558">the healthiest diet researchers know of</a> for longevity and prevention of chronic diseases like heart disease, cancer, hypertension and many other conditions. </p>
<p>The modern Western diet suffers from an <a href="https://doi.org/10.1038/ijo.2012.225">increase in quantity of calories</a> consumed with a concurrent <a href="https://doi.org/10.3945/ajcn.114.100867">decrease in the quality of calories</a> consumed. And researchers now know that calories from different foods <a href="https://doi.org/10.1056/NEJMoa1014296">have different effects</a> on fullness, insulin response, the process of turning carbs to body fat, and metabolic energy expenditure.</p>
<p>Where your health is concerned, count more on the quality of the calories you consume than the calorie count.</p>
<p>[<em>Get the best of The Conversation, every weekend.</em> <a href="https://theconversation.com/us/newsletters/weekly-highlights-61?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=weeklybest">Sign up for our weekly newsletter</a>.]</p><img src="https://counter.theconversation.com/content/156900/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Terezie Tolar-Peterson does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>In almost every way, one cheeseburger does not equal six apples. With the goal of optimal health in mind, a calorie is not a calorie is not a calorie.Terezie Tolar-Peterson, Associate Professor of Food Science, Nutrition & Health Promotion, Mississippi State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1185712019-07-01T10:52:11Z2019-07-01T10:52:11ZSugar substitutes: Is one better or worse for diabetes? For weight loss? An expert explains<figure><img src="https://images.theconversation.com/files/280570/original/file-20190620-149814-17p8d8c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Sugar and artificial sweeteners comes in many shapes and colors.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/flat-lay-composition-different-types-sugar-1057731923?studio=1">New Africa/Shutterstock.com</a></span></figcaption></figure><p>Wandering through the grocery store, it is easy to be overwhelmed by the numerous brands and health claims on the dozens of sugar substitutes. It can be particularly confusing for those with diabetes or pre-diabetes who must keep their blood sugar in check and control their weight. </p>
<p>With the <a href="https://www.who.int/news-room/fact-sheets/detail/diabetes">growing diabetes and obesity epidemic</a>, there has been increasing awareness around the use of added sugars in foods. The most recent edition of the <a href="https://health.gov/dietaryguidelines/2015/">U.S. Dietary Guidelines for Americans</a> recommends that added sugars should be kept to less than 10% of the calories consumed, which turns out to be roughly 270 calories per day. </p>
<p>This is because “added sugars” add sweetness or flavor but add very little nutritional value. Because of this trend, the food industry has embarked on a quest to find or develop the perfect substitute to replace sugar – with the same taste and none of the calories that lead to weight gain. </p>
<p>As a pharmacist who is also board certified in advanced diabetes management, I talk to patients every day about blood sugars and ways to help them take control of their diabetes. They often ask me whether the perfect substitute to sugar has been found. The short answer is no. Here is the long answer.</p>
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<img alt="" src="https://images.theconversation.com/files/281801/original/file-20190628-94716-tinmxq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/281801/original/file-20190628-94716-tinmxq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281801/original/file-20190628-94716-tinmxq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281801/original/file-20190628-94716-tinmxq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281801/original/file-20190628-94716-tinmxq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281801/original/file-20190628-94716-tinmxq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281801/original/file-20190628-94716-tinmxq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Many artificial sweeteners are available at the grocery store.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/subang-jaya-malaysia-23rd-december-2017-781850755?studio=1">Zety Akhzar/Shutterstock.com</a></span>
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<h2>Sugar alcohols</h2>
<p>Sugar substitutes can be categorized into two main groups: sugar alcohols and high intensity sweeteners. The sugar alcohols include sorbitol, xylitol, lactitol, mannitol, erythritol and maltitol. <a href="https://www.fda.gov/food/food-additives-petitions/high-intensity-sweeteners">High-intensity sweeteners</a> include saccharin, aspartame, acesulfame potassium (Ace-K), sucralose, neotame, advantame, stevia, and Siraitia grosvenorii Swingle fruit extract (SGFE).</p>
<p><a href="http://www.diabetes.org/food-and-fitness/food/what-can-i-eat/understanding-carbohydrates/sugar-alcohols.html">Sugar alcohols</a> are often found in toothpaste, chewing gum, and some “sugar-free” foods. They are carbohydrates with a chemical structure that resembles sugar, but also the components that make them an alcohol. They are about 25-100% sweeter than sugar and have <a href="https://doi.org/10.1016/j.foodres.2019.03.019">a similar taste</a>. But here is the catch: They are not calorie free. Most have <a href="http://doi.org/10.1016/j.jand.2012.03.009">between 1.5 and two calories per gram</a>. Now compare the calorie count to sugar, also known as sucrose, which has four calories per gram – twice as much. </p>
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<a href="https://images.theconversation.com/files/281805/original/file-20190628-94708-lua3oo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/281805/original/file-20190628-94708-lua3oo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281805/original/file-20190628-94708-lua3oo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=847&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281805/original/file-20190628-94708-lua3oo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=847&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281805/original/file-20190628-94708-lua3oo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=847&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281805/original/file-20190628-94708-lua3oo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1064&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281805/original/file-20190628-94708-lua3oo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1064&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281805/original/file-20190628-94708-lua3oo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1064&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Which foods have a low glycemic index and are better choices for those trying to control their blood sugar.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/chart-infographics-vector-drawn-glycemic-index-390100423?src=lLctBPmzaHfK2TKO97-FXw-1-5&studio=1">Irina Izograf</a></span>
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<p>Although sugar alcohols contain fewer calories, they will still increase a patient’s blood sugar, especially when eaten in excess. When compared to sugar, the effect is less dramatic though. This is because of how these molecules are processed in the body. We measure this using the glycemic index. </p>
<p>The glycemic index is a reference to how quickly a food is broken down and absorbed. The higher the number, the more quickly the food breaks down and the faster the sugar goes into the blood. Sucrose has a <a href="https://www.glycemicindex.com/">glycemic index</a> of 65; whereas sugar alcohols, like xylitol, have a glycemic index of around seven. This means that sugar alcohols are harder to digest, and cause a slower and lower increase in post-meal blood sugars – which is typically better for people with diabetes. Because sugar alcohols are harder for the body to break down though, some of them remain in the gut, and if a person consumes too much they may experience <a href="http://doi.org/10.1016/j.jand.2012.03.009">digestive complaints like</a> gas, cramping and diarrhea.</p>
<p>Here is the other downside to foods containing sugar alcohols: They often have <a href="http://www.diabetes.org/food-and-fitness/food/what-can-i-eat/understanding-carbohydrates/sugar-alcohols.html">higher quantities of fat or salt</a> to make up for the lower sugar content.</p>
<h2>Artificial sweeteners</h2>
<p>High-intensity sweeteners, are zero- or low-calorie alternatives to sugar. They are made from a variety of sources, and are 100 to 20,000 times as sweet as sugar. Some leave a bitter or metallic taste behind. Two newer substitutes – stevia and SGFE – come from plants and are at times referred to as “natural” substitutes. </p>
<p>According to the <a href="https://care.diabetesjournals.org/content/42/Supplement_1">American Diabetes Association 2019 guidelines</a>, the use of high-intensity sweeteners may decrease calorie and carbohydrate intake. However, you cannot replace these “free” calories with calories from other food sources, you will lose or the benefits on blood sugar control and weight loss. </p>
<p>Researchers have seen this in some of the studies on high-intensity sweeteners. Some of the trials show <a href="http://doi.org/10.1503/cmaj.161390">no difference or even a possible increase in weight</a>. But in other studies where intake of food is better regulated and patients don’t replace these free calories with other high-caloric foods, <a href="http://doi.org/10.3945/ajcn.113.082826">the weight loss is maintained</a>. </p>
<h2>The takeaway</h2>
<p>All sugar substitutes are labeled as food additives and are under the regulation of the U.S. Food and Drug Administration. The latest trend has been labeling some of the sugar substitutes as “derived from plants” or “natural.” That does not necessarily mean that these are safer or more effective in blood sugar control or weight loss. If it is used in excess, side effects such as bloating or diarrhea may still result. </p>
<p>Several concerns by researchers have been raised about high-intensity sweeteners – saccharin and aspartame – and cancer. To date, the National Cancer Institute has concluded that there is no clear evidence that any of the high-intensity sweeteners is <a href="https://www.cancer.gov/about-cancer/causes-prevention/risk/diet/artificial-sweeteners-fact-sheet">associated with an increased risk of cancer</a>. </p>
<p>As a pharmacist specializing in advanced diabetes, I talk to patients every day about how to control their blood sugar level and their diabetes. There are three main ways to do that: medication, increased activity and diet. The last two are probably more important in the long run. </p>
<p>If diet and activity level never change, it is really hard to help patients bring their blood sugars down. Medication after medication will likely have to be added. With this comes the potential for side effects. So if I can persuade patients to make changes to their diet, like switching to a beverage with a sugar substitute, it makes a huge difference in helping to control blood sugars and the dose of medications.</p>
<p>The overall focus for diabetes management should be on reducing the consumption of sugar-sweetened beverages and foods. If you can switch one of these sugar-sweetened products to a food that has a high-intensity sugar substitute, that is better. But best of all is consuming <a href="https://care.diabetesjournals.org/content/42/Supplement_1">food and drinks that are not highly processed</a> and do not have added sugars.</p><img src="https://counter.theconversation.com/content/118571/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jamie Pitlick does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>There is a huge variety of sugar substitutes available. What’s the difference? Is one better for controlling blood sugar levels for diabetes? Is one better for individuals trying to lose weight?Jamie Pitlick, Associate Professor of Pharmacy Practice , Drake UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/949052018-05-14T02:13:57Z2018-05-14T02:13:57ZHealth Check: what should I eat to improve my skin?<figure><img src="https://images.theconversation.com/files/218718/original/file-20180514-178731-pm9wqe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fruits and vegetables are wonderful for our bodes in many ways.</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/-gOUx23DNks">ja ma/Unsplash</a></span></figcaption></figure><p>“Get radiant skin!” “Banish your pimples!” “Glow from the inside out!”</p>
<p>These are some statements that pop up when asking Google the age-old question: what should I eat to improve my skin? </p>
<p>Recommendations usually include cutting out <a href="https://www.popsugar.com.au/beauty/How-Chocolate-Affects-Your-Skin-37200168">chocolate</a>, other <a href="https://blog.kettleandfire.com/11-foods-that-are-bad-for-your-skin/">junk foods</a> and <a href="http://www.oprah.com/health_wellness/what-cutting-out-dairy-did-to-my-skin">dairy products</a>. But is there evidence to actually support this?</p>
<h2>Chocolate</h2>
<p>Researchers <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/j.1440-0960.1951.tb01410.x">started exploring</a> the link between diet and skin health, particularly acne, in the mid-1900s. Dermatology textbooks from the 1930s advised restricting carbohydrates, sweets and junk foods to improve acne. But these recommendations were based on doctors’ experiences and observations, not quality research.</p>
<p>Chocolate is one junk food that often gets blamed as an aggravating factor of acne. In a <a href="https://jamanetwork.com/journals/jama/article-abstract/350738?redirect=true">1969 study</a>, 65 people with acne were asked to eat one chocolate bar per day for four weeks. They were either given a bar that contained ten times the amount of chocolate found in a typical bar, or a bar that looked identical but contained no chocolate.</p>
<p>Results showed participants who ate the chocolate bars did not have more breakouts than those who didn’t eat the chocolate.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/218420/original/file-20180510-34018-ea5f76.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/218420/original/file-20180510-34018-ea5f76.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/218420/original/file-20180510-34018-ea5f76.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=428&fit=crop&dpr=1 600w, https://images.theconversation.com/files/218420/original/file-20180510-34018-ea5f76.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=428&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/218420/original/file-20180510-34018-ea5f76.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=428&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/218420/original/file-20180510-34018-ea5f76.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=538&fit=crop&dpr=1 754w, https://images.theconversation.com/files/218420/original/file-20180510-34018-ea5f76.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=538&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/218420/original/file-20180510-34018-ea5f76.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=538&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Studies on whether chocolate has an effect on your skin are so far inconclusive.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/6regCWGgEsc">Charisse Kenion/Unsplash</a></span>
</figcaption>
</figure>
<p>Similar results were found in a <a href="https://www.ncbi.nlm.nih.gov/pubmed/4251510">1971 study</a>. Twenty-seven students who reported being sensitive to dietary acne triggers ate large amounts of chocolate, milk, roasted peanuts or soft drinks for one week. No significant difference in the number of breakouts was observed between the groups. </p>
<p>But these studies also had some major limitations. The 1969 study was sponsored by the Chocolate Manufacturers Association of the United States of America. And both studies did not assess participants’ intake of other foods during the study period, which may have influenced their complexion.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/research-check-does-eating-chocolate-improve-your-brain-function-55229">Research Check: does eating chocolate improve your brain function?</a>
</strong>
</em>
</p>
<hr>
<p>More recently, a <a href="https://www.ncbi.nlm.nih.gov/pubmed/21920227">2011 study</a> including ten men aged between 18-35 found significant changes occurred in the severity of acne after a single intake of pure chocolate (100% cocoa). There was a strong association between the amount of chocolate consumed and the number of breakouts four and seven days after they ate the chocolate.</p>
<p>So overall, study findings show conflicting results, and clear recommendations about chocolate cannot yet be made. </p>
<p>But better-quality research does suggest other dietary strategies worth trying if you want to improve your skin. These include eating more fruits and vegetables as well as foods with a lower glycaemic load.</p>
<h2>Glycaemic load</h2>
<p>The <a href="https://www.health.qld.gov.au/__data/assets/pdf_file/0026/143567/paeds_gi.pdf">glycaemic index (GI)</a> is a ranking between 0-100 given to carbohydrate-containing foods to describe how quickly the carbohydrates are digested into glucose (sugar) and absorbed into our blood. The lower the GI, the slower the rise in blood glucose levels when the food is consumed. Most junk foods (candy, chips and cakes) have a high GI. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/gi-diets-dont-work-gut-bacteria-and-dark-chocolate-are-a-better-bet-for-losing-weight-51146">GI diets don't work – gut bacteria and dark chocolate are a better bet for losing weight</a>
</strong>
</em>
</p>
<hr>
<p>Glycaemic load (GL) builds on the concept of GI but also considers the amount of food being eaten. This provides a more accurate picture of the overall effect the food has on blood glucose levels. </p>
<p>Once the glucose enters the blood, a hormone called insulin moves it into our cells to be used for energy. Diets with a high GL trigger a higher response in insulin. This high level of insulin increases a hormone called the insulin-like growth factor (IGF), which <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5318522/">has been associated</a> with skin breakouts – like pimples.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/218421/original/file-20180510-34027-sbdk6v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/218421/original/file-20180510-34027-sbdk6v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/218421/original/file-20180510-34027-sbdk6v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/218421/original/file-20180510-34027-sbdk6v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/218421/original/file-20180510-34027-sbdk6v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/218421/original/file-20180510-34027-sbdk6v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/218421/original/file-20180510-34027-sbdk6v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/218421/original/file-20180510-34027-sbdk6v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Junk foods have a high glycaemic index.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<p>In a 2008 <a href="https://www.ncbi.nlm.nih.gov/pubmed/18178063">randomised control trial</a> (considered the gold standard in scientific research as it compares findings between two groups), 31 males with acne, aged 15-25, were asked to follow either a low-GL or a high-GL diet for 12 weeks. The low-GL group was instructed to substitute high-GI foods (processed cereals, potatoes and white bread and rice) with lower-GI foods (lean meats, fruits and wholegrain bread and pasta). </p>
<p>The high-GL group was encouraged to include carbohydrates as a regular part of their diet and wasn’t educated about GI. Those following the low-GL diet saw their acne improve and lost more weight. </p>
<p>A <a href="https://www.ncbi.nlm.nih.gov/pubmed/17448569">2007 randomised controlled trial</a> had similar findings. But because participants in both studies who were following the low-GL diet lost weight, it’s also possible improvements in their skin were due to weight loss and not the diet itself.</p>
<h2>Fruit and vegetables</h2>
<p>Fruits and vegetables are wonderful for our bodies in many ways, but <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/ajpy.12163">research shows</a> they can also give our skin a natural, healthy glow – by tinting it yellow and red. </p>
<p>Our skin colour is influenced by three pigments – haemoglobin, carotenoids and melanin. Many fruits and vegetables contain carotenoids. These are responsible for the deep green colour of broccoli and spinach, the vibrant orange colour of carrots and oranges, and the red hue of capsicums and tomatoes.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/216601/original/file-20180427-175035-1ggn09b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/216601/original/file-20180427-175035-1ggn09b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/216601/original/file-20180427-175035-1ggn09b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/216601/original/file-20180427-175035-1ggn09b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/216601/original/file-20180427-175035-1ggn09b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/216601/original/file-20180427-175035-1ggn09b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/216601/original/file-20180427-175035-1ggn09b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Eating lots of oranges could give your skin a healthy, golden glow.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/xSGCbGYQtO4">freestocks.org/Unsplash</a></span>
</figcaption>
</figure>
<p>When you eat fruits and vegetables, these pigments can <a href="https://academic-oup-com.libraryproxy.griffith.edu.au/jn/article/132/3/399/4687282">accumulate</a> in your skin, <a href="https://www.ncbi.nlm.nih.gov/pubmed/25014019">leading to a healthy</a> golden glow. The same benefits haven’t been seen with supplements, so it’s best to get your carotenoid hit from eating lots of different fruits and vegetables.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/food-as-medicine-why-do-we-need-to-eat-so-many-vegetables-and-what-does-a-serve-actually-look-like-76149">Food as medicine: why do we need to eat so many vegetables and what does a serve actually look like?</a>
</strong>
</em>
</p>
<hr>
<h2>What about milk?</h2>
<p>Milk naturally contains anabolic steroids, growth hormones and other growth factors. In a complicated metabolic pathway, these factors lead to a higher release of insulin and insulin-like growth factor, which can stimulate the <a href="https://www.ncbi.nlm.nih.gov/pubmed/21335995">development and progression</a> of acne.</p>
<p>A number of studies have examined the alleged connection between milk and acne. In 2005, 50,000 women <a href="https://www.ncbi.nlm.nih.gov/pubmed/15692464">recalled their high school diet</a> and were asked if they had ever been diagnosed with severe acne by their doctor. </p>
<p>Researchers found those who had a higher reported intake of milk (particularly skim milk) more commonly suffered from acne. <a href="https://www.ncbi.nlm.nih.gov/pubmed/17083856">A 2006 study</a> with around 6,000 teenage girls and a <a href="https://www.jaad.org/article/S0190-9622(07)02402-4/abstract">2008 study</a> with around 4,700 teenage boys showed similar results. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/218716/original/file-20180514-34018-1d9tbdz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/218716/original/file-20180514-34018-1d9tbdz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/218716/original/file-20180514-34018-1d9tbdz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=937&fit=crop&dpr=1 600w, https://images.theconversation.com/files/218716/original/file-20180514-34018-1d9tbdz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=937&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/218716/original/file-20180514-34018-1d9tbdz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=937&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/218716/original/file-20180514-34018-1d9tbdz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1178&fit=crop&dpr=1 754w, https://images.theconversation.com/files/218716/original/file-20180514-34018-1d9tbdz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1178&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/218716/original/file-20180514-34018-1d9tbdz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1178&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Milk has been associated with acne development.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<p>But no randomised controlled trials have been conducted that examine the association between milk and acne. This means whether dairy is a cause of acne hasn’t yet been established. High-quality research is needed before specific recommendations can be made. </p>
<p>If you are trying to improve your skin’s complexion, you could try these strategies: </p>
<ul>
<li><p>reduce high-GL foods by decreasing the amount of processed, junk food you eat</p></li>
<li><p>add <a href="http://www.glycemicindex.com">low-GL foods</a> that won’t spike your blood glucose levels (vegetables, sweet potatoes, barley, beans and multigrain bread)</p></li>
<li><p>eat a diverse range of fruits and vegetables to get a healthy glow.</p></li>
</ul><img src="https://counter.theconversation.com/content/94905/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emily Burch does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Research shows eating foods with a lower glycaemic load, and more fruits and vegetables, will improve your complexion.Emily Burch, PhD Candidate, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/945702018-04-11T20:04:52Z2018-04-11T20:04:52ZResearch Check: is it true pasta doesn’t make you gain weight, and could even help you lose it?<figure><img src="https://images.theconversation.com/files/214215/original/file-20180411-536-682yhi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Pasta has a low glycaemic index.</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/EP8Qsfh1EQQ">Photo by chuttersnap on Unsplash</a></span></figcaption></figure><p>Most people think eating pasta will lead to weight-gain, but a <a href="http://bmjopen.bmj.com/content/8/3/e019438">recent study</a> found otherwise. It’s no suprise such a conclusion made headlines. </p>
<p>Business Insider <a href="https://www.businessinsider.com.au/study-finds-pasta-wont-make-you-gain-weight-2018-4?r=US&IR=T">claimed</a>:</p>
<blockquote>
<p>Eating pasta 3 times a week won’t make you gain weight, according to a new study – and it could even help you lose it</p>
</blockquote>
<p>And The Daily Meal <a href="https://www.thedailymeal.com/eat/pasta-weight-loss-study/040318">said</a>:</p>
<blockquote>
<p>Eat Pasta to Lose Weight, Study Says</p>
</blockquote>
<p>But before you get the pasta pot boiling, there’s an important provision to keep in mind. The groups of people who ate pasta and lost weight were following an overall low glycaemic index (GI) diet. This means that the weight loss wasn’t the result of eating pasta alone, but the effect of the low GI diet.</p>
<h2>What’s glycaemic index?</h2>
<p><a href="https://www.health.qld.gov.au/__data/assets/pdf_file/0026/143567/paeds_gi.pdf">Glycaemic index</a>, or GI, ranks foods that contain carbohydrates based from 0-100 on how quickly and to what level they raise your blood sugar after you’ve eaten them. The higher the GI, the faster and higher the rise in blood glucose concentration. </p>
<p>Foods ranked as having a low glycaemic index have a <a href="http://www.glycemicindex.com/index.php">GI of less than 55</a>. Medium GI foods are ranked between 55-70, while those with a GI greater than 70 have a high GI index.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/214234/original/file-20180411-570-8l2t5m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/214234/original/file-20180411-570-8l2t5m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/214234/original/file-20180411-570-8l2t5m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=431&fit=crop&dpr=1 600w, https://images.theconversation.com/files/214234/original/file-20180411-570-8l2t5m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=431&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/214234/original/file-20180411-570-8l2t5m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=431&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/214234/original/file-20180411-570-8l2t5m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=541&fit=crop&dpr=1 754w, https://images.theconversation.com/files/214234/original/file-20180411-570-8l2t5m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=541&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/214234/original/file-20180411-570-8l2t5m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=541&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Participants who ate pasta were also on a low GI diet.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<p>Pasta has a lower GI as does some multigrain bread, rolled oats, apples, oranges, sweet potato, sweetcorn, lentils and chickpeas, milk and cashew nuts. <a href="https://www.health.qld.gov.au/__data/assets/pdf_file/0026/143567/paeds_gi.pdf">High GI foods include</a> some white breads, corn flakes, jasmine rice, potato, watermelon and rice crackers.</p>
<p>Eating foods from the low-GI list more frequently than those on the medium or high GI list leads to an overall dietary pattern with a lower mean GI value. This is thought to be important in terms of regulating blood sugars and appetite, particularly for people with <a href="https://www.ncbi.nlm.nih.gov/pubmed/29562676">type 2 diabetes</a> and those who are <a href="https://www.ncbi.nlm.nih.gov/pubmed/23786819">overweight or obese</a>.</p>
<h2>How was the study conducted?</h2>
<p>The study design is called a <a href="https://en.wikipedia.org/wiki/Systematic_review">systematic review</a>, which combines a number of already published studies answering a similar question to generate an overall conclusion. In this case, the researchers analysed the results from 29 randomised controlled trials in adults – where diets including pasta (the main intervention) were compared with another type of diet (the control). </p>
<p>The trials reviewed had investigated the impact of eating pasta on body weight and other indicators of body composition including changes in body fat, waist circumference, waist-to-hip ratio, abdominal diameter and body mass index (BMI). The studies lasted for a median of 12 weeks and included 2,448 participants.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-whats-the-best-diet-for-weight-loss-21557">Health Check: what's the best diet for weight loss?</a>
</strong>
</em>
</p>
<hr>
<p>This review originally set out to see whether eating more pasta, independent of what else you were eating, affected body weight. However, the researchers didn’t find any studies that had tested whether eating <em>more</em> pasta impacted body weight. All of the studies included in the review looked at the effect of eating pasta as part of an overall dietary prescription to follow a low GI diet.</p>
<p>That the pasta diets tested were, in fact, low GI diets is a major provision to interpreting the results. This means that the pasta groups (active arms) included people following an eating pattern with an overall low GI, compared to the control arms where the dietary patterns had a higher GI.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/214223/original/file-20180411-566-1z0qc9i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/214223/original/file-20180411-566-1z0qc9i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/214223/original/file-20180411-566-1z0qc9i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=428&fit=crop&dpr=1 600w, https://images.theconversation.com/files/214223/original/file-20180411-566-1z0qc9i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=428&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/214223/original/file-20180411-566-1z0qc9i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=428&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/214223/original/file-20180411-566-1z0qc9i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=538&fit=crop&dpr=1 754w, https://images.theconversation.com/files/214223/original/file-20180411-566-1z0qc9i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=538&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/214223/original/file-20180411-566-1z0qc9i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=538&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Rolled oats and apples are both low GI foods.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<h2>What were the results?</h2>
<p>The systematic review’s main findings were that eating pasta was associated with a greater mean reduction in body weight of about 630 grams, and a reduction in BMI of 0.26 kg per square metre more in the pasta eating groups compared to the controls. There were no significant differences between groups when it came to other indicators of body weight or body composition. </p>
<p>The authors concluded that eating pasta in the context of low GI dietary patterns does not negatively affect body fatness, and reduces body weight and BMI, compared with higher GI dietary patterns.</p>
<p>The amount of weight loss was similar (mean of 630 grams more in the pasta/low-GI group) in the studies that ran for less than 24 weeks, compared to those that ran for longer (mean of 570 grams more for the pasta/low GI group). When the sub-group of studies were examined in those with type 2 diabetes or adults with overweight or obesity, the results were similar. </p>
<p>This is important because it means people in these categories can eat and enjoy pasta without compromising their weight status. The catch is how much pasta was eaten on each occasion.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/got-pre-diabetes-heres-five-things-to-eat-or-avoid-to-prevent-type-2-diabetes-80838">Got pre-diabetes? Here's five things to eat or avoid to prevent type 2 diabetes</a>
</strong>
</em>
</p>
<hr>
<h2>Issues with portion sizes</h2>
<p>There were only 11 trials in which the amount of pasta eaten could be quantified, and the authors did not report how the dietary intake data was extracted from these trials and converted to serve sizes. This pasta intake data is a potential source of error. </p>
<p>The <a href="https://www.eatforhealth.gov.au/food-essentials/five-food-groups/grain-cereal-foods-mostly-wholegrain-and-or-high-cereal-fibre">Australian Guide to Healthy Eating</a> defines one serve of pasta as being equivalent to half a cup of cooked pasta. But internationally what is called a <a href="https://www.ncbi.nlm.nih.gov/pubmed/28899402">serving size</a> varies.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/214220/original/file-20180411-577-1vcxkfn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/214220/original/file-20180411-577-1vcxkfn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/214220/original/file-20180411-577-1vcxkfn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/214220/original/file-20180411-577-1vcxkfn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/214220/original/file-20180411-577-1vcxkfn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/214220/original/file-20180411-577-1vcxkfn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/214220/original/file-20180411-577-1vcxkfn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/214220/original/file-20180411-577-1vcxkfn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">There’s no international consensus on what constitutes one serving of pasta.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<p>The median number of pasta servings across the studies was reported as 3.3 per week, ranging from from nearly two to seven per week. In this group of studies, the mean weight loss was 700 grams more in the pasta eating low GI groups compared to higher GI groups. </p>
<p>Of note is that the median pasta intake in the pasta groups was not very high. The median of 3.3 equates to only 1.7 cups of cooked pasta per week, varying from 0.9-3.5 cups. In the trials where there was also a kilojoule restriction, the median pasta intake was 2.3 servings (1.2 cups) per week. </p>
<p>The authors also looked at whether there was a dose-response effect for eating pasta. This means they checked whether those who ate more pasta, lost more weight. The answer was no – there was no dose-response effect.</p>
<h2>So, what’s the verdict?</h2>
<p>So the conclusion of this study could equally, and perhaps more accurately, be that following a low GI diet reduces body weight and BMI compared with a high GI diet. And following a low-GI diet does not have a negative effect on body composition. </p>
<p>The authors suggest that future trials are needed to assess the effect of eating pasta over longer periods of time or in the context of other “healthy” dietary patterns. Overall though, rigorous reviews like the current one are excellent in helping to dispel diet myths, <a href="https://theconversation.com/six-common-questions-about-eating-carbs-during-pregnancy-answered-84595">particularly those related to carbohydrates</a>. <strong>- Clare Collins</strong></p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-is-a-balanced-diet-anyway-72432">What is a balanced diet anyway?</a>
</strong>
</em>
</p>
<hr>
<h2>Peer Review</h2>
<p>I believe this is a fair, and mostly accurate and balanced assessment of the study and its findings. </p>
<p>However, I would say it’s more accurate the conclusion of this study is that: Following a low GI diet <em>that includes pasta</em> reduces body weight and BMI more compared with a high(er) GI diet <em>that doesn’t include pasta</em>. <strong>- Rebecca Reynolds</strong></p><img src="https://counter.theconversation.com/content/94570/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Clare Collins is affiliated with the Priority Research Centre for Physical Activity and Nutrition, the University of Newcastle, NSW. She is an NHMRC Senior Research and Gladys M Brawn Research Fellow. She has received research grants from NHMRC, ARC, Hunter Medical Research Institute, Meat and Livestock Australia, Diabetes Australia, Heart Foundation, Bill and Melinda Gates Foundation, nib foundation. She has consulted to SHINE Australia, Novo Nordisk, Quality Bakers and the Sax Institute. She was a team member conducting systematic reviews to inform the Australian Dietary Guidelines update and 2017 evidence review on dietary patterns for the Heart Foundation.</span></em></p><p class="fine-print"><em><span>Rebecca Charlotte Reynolds owns The Real Bok Choy, a nutrition and lifestyle consultancy. </span></em></p>A recent study was reported to have found that eating pasta wouldn’t make you put on weight, This is actually true, so long as you’re following a low GI diet.Clare Collins, Professor in Nutrition and Dietetics, University of NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/511462015-11-23T13:26:24Z2015-11-23T13:26:24ZGI diets don’t work – gut bacteria and dark chocolate are a better bet for losing weight<figure><img src="https://images.theconversation.com/files/102834/original/image-20151123-18255-1etu4sn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Listen to your gut – dark chocolate is rich in polyphenols. </span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-231874846/stock-photo-young-attractive-woman-eating-bitter-chocolate.html?src=tlrmguKAQcQMXRE1z3LDtA-1-71">Chocolate by Shutterstock</a></span></figcaption></figure><p>The mainstays of most of the diet regimens of the last 30 years have been the GI (glycaemic index) rating score as well as its cousin the glycaemic load. Famous best-selling diet books such as the G-Plan Diet, the South Beach diet all used the index in some way and changed the way we thought about carbohydrates. Now a detailed new study <a href="http://bit.ly/1QVyqyW">published in Cell</a> pays this score – and how we use it – some closer scrutiny. </p>
<p>The GI theory goes that there are many different types of carbs and they can be graded into how rapidly the body converts them into glucose. The faster the burn rate, the higher the index and the more rapid the rise in blood sugar. This surge in blood sugar also triggers a rise in insulin and the combination of these events if sustained over time is believed to lead to unhealthy metabolic changes leading eventually to obesity and diabetes. </p>
<p>This nutritional dogma has been the backbone of the advice to avoid eating high GI foods such as pasta, rice and potatoes and replace them with low GI alternatives such as beans or lentils. In many cases people give up carbs completely or avoid refined carbs and instead go for approaches like the <a href="http://authoritynutrition.com/atkins-diet-101/">Atkins Diet</a>. This cutting down on “bad” carbs also sounds like common sense and most doctors, health professionals and members of the public, including myself when I started writing my book <a href="http://www.wnblog.co.uk/2015/04/the-ten-most-surprising-diet-facts-from-the-diet-myth-by-tim-spector/">The Diet Myth</a>, assume that proper scientific and clinical trials have been carried out that back up these ideas. But what if none of it were true and we had been misled?</p>
<p>When I started researching four years ago I could find plenty of laboratory animal studies showing the benefits of a low GI diet. But while studies of diabetic subjects generally confirmed <a href="http://www.ncbi.nlm.nih.gov/pubmed/19160276">some advantage</a> of a low GI diet, in non-diseased people it was a different story. There was a distinct lack of any decent human trial that proved convincingly that a GI-based diet was any better than <a href="http://www.ncbi.nlm.nih.gov/pubmed/25514303">equivalent diets based on cutting calories</a>. </p>
<p>While studies did show <a href="http://diabetes.diabetesjournals.org/content/26/12/1178.abstract?ijkey=afee3c6554482b9bb4c969fa34852438dbf2f970&keytype2=tf_ipsecsha">that low GI foods</a> and diets could <a href="http://www.ncbi.nlm.nih.gov/pubmed/24265366">alter blood sugar profiles</a> no study has shown that when the amount of carbs and calories are kept constant the lower GI score for the food didn’t influence body weight. So humans seem to be responding differently to laboratory mice, and although many people do lose weight in the short-term on these diets, it may be because they are paying more attention to what they eat rather than any validity of the food scoring process.</p>
<h2>It’s those microbes again</h2>
<p>What the new study – from an Israeli team led by Eran Segal – found was that by closely studying 800 volunteers who kept careful food diaries and had wearable devices that continually monitored their blood glucose levels, an amazing pattern of diversity emerged. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/102835/original/image-20151123-18227-k6gtoe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/102835/original/image-20151123-18227-k6gtoe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/102835/original/image-20151123-18227-k6gtoe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=532&fit=crop&dpr=1 600w, https://images.theconversation.com/files/102835/original/image-20151123-18227-k6gtoe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=532&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/102835/original/image-20151123-18227-k6gtoe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=532&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/102835/original/image-20151123-18227-k6gtoe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=669&fit=crop&dpr=1 754w, https://images.theconversation.com/files/102835/original/image-20151123-18227-k6gtoe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=669&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/102835/original/image-20151123-18227-k6gtoe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=669&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Gut bacteria – unique to you.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/pnnl/8146322408/in/photolist-dpS2QC-cNzEzb-sgiRUL-sxJ8Ky-sgj7j9-sxJ9os-svAPTm-FCtqh-cNA5L7-cZn9dU-66DRfE-nRxDki-p7cQxe-nzmo9d-bpfAWr-gbNDja-9UoACW-8uLqb2-h392az-8TDkgU-75R8Qb-5knR8g-wX3fme-mF4F1a-mF4YTT-mF4Hu8-mF4HHK-mF6xQo-mF4Z1M-mF4ZsP-mF6y51-mF4GMg-mF4Zh8-mF4GY8-mF4GZk-mF4XQv-mF6Bv9-mF51EZ-mF52sa-oSLq42-GupMC-mGsYVf-bVNWSw-oC36JB-2b6CBf-mF4K2X-mF53eR-mF6A8Q-mF4Jfr-mF4KCX">Pacific Northwest National Laboratory</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span>
</figcaption>
</figure>
<p>People eating the same foods and had the same GI scores had very different glucose responses. Some of this was due to existing weight and age differences in the study’s subjects – but differences remained even in similar people that they couldn’t explain. That was until they looked inside their intestines at the thousands of species of microbes we have inside us. We all have around <a href="http://www.nytimes.com/2013/05/19/magazine/say-hello-to-the-100-trillion-bacteria-that-make-up-your-microbiome.html">100 trillion bacteria</a> mainly living in our colons (outnumbering our cells by ten to one) and unlike our genetic code, which is 99.9% similar across individuals, we probably only share less than 20% of our microbes on average. </p>
<p>Our gut microbes live off the fibre in foods that make it to the lower part of the intestines. The researchers found that the highly variable microbial profile in the guts of the volunteers determined how quickly the food was broken down and the rate at which glucose appeared in the blood. This was a much stronger effect than the type of carb being eaten. Some people could eat potatoes without any surge in blood sugar and others with the wrong set of microbes just had to look at one and their blood levels peaked. </p>
<p>Unlike our genes, our microbes are to some extent changeable. The team went on to successfully modify the diets of the subjects with the worst looking profiles.</p>
<h2>Personalised nutrition</h2>
<p>These results could be a game-changer for nutrition. We can now move from our outdated obsession with inaccurate calorie counts and GI scores of food items to working out how our foods interact with our microbes. </p>
<p>We should focus on the fibre type and content of each item and assess its ability to act as a fertiliser for microbes via chemicals called polyphenols. For example, purple coloured potatoes have three times more polyphenols than those with normal skins and <a href="http://www.ncbi.nlm.nih.gov/pubmed/24577454">appear healthier in humans</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/102833/original/image-20151123-18233-1yzhwsk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/102833/original/image-20151123-18233-1yzhwsk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/102833/original/image-20151123-18233-1yzhwsk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/102833/original/image-20151123-18233-1yzhwsk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/102833/original/image-20151123-18233-1yzhwsk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/102833/original/image-20151123-18233-1yzhwsk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/102833/original/image-20151123-18233-1yzhwsk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Which to choose? Check in with your little friends.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-45056437/stock-photo-wooden-box-filled-with-different-colored-fingerling-potatoes.html?src=5-OHjffXkDsyhiyAdnUUiQ-1-66">Potatoes by Shutterstock</a></span>
</figcaption>
</figure>
<p>White rice lacks polyphenols so is unhealthy while <a href="http://www.ncbi.nlm.nih.gov/pubmed/23209885">dark chocolate</a> has plenty and doesn’t cause a glucose surge. This could also be a game changer for the millions suffering from or (if overweight) at high risk of diabetes. </p>
<p>Rather than avoiding all foods which might be harmful and reducing your fibre and diversity, profiling your gut microbes from a piece of toilet paper could tell you whether you should be eating potatoes or not. By using the breakthrough techniques of gene sequencing we can now accurately and cheaply identify the different patterns of microbes. While the Israeli team are working on a commercial testing kit – others can now join crowdfunded research projects <a href="http://www.americangut.org">in the US</a> and <a href="http://www.BritishGut.org">the UK</a> that want people to be able to test themselves and properly map and explore the amazing diversity of our gut microbes. This is the exciting new era of personalised nutrition and for many people a jacket potato could be back on the menu.</p><img src="https://counter.theconversation.com/content/51146/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tim Spector is affiliated with the crowd funded American Gut Project and is director of the related British Gut microbiome project. He is author of a book on gut microbes: 'The Diet Myth': the secret behind what we eat, by W&N 2015</span></em></p>Science suggests that diets tailored to your own gut work better than those based on the glycaemic index.Tim Spector, Professor of Genetic Epidemiology, King's College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/443552015-09-21T04:32:36Z2015-09-21T04:32:36ZHealth Check: ‘food comas’, or why eating sometimes makes you sleepy<figure><img src="https://images.theconversation.com/files/95309/original/image-20150918-12379-nt7z2l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Here's a clue: what you eat is just as important as the size of your meal.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/davechiu/375131863/">Dave Chiu/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>We’ve all done it, enjoyed a delicious meal only to nod off in a comfy chair for a while. For some of us, this is just a habit. But for others, it’s unavoidable. So what is it about food that can make us so sleepy?</p>
<p>When we’re eating, the stomach is producing gastrin, a hormone that promotes the secretion of digestive juices. As the food enters the small intestine, the cells in the gut secrete even more hormones (enterogastrone) that signal other bodily functions, including blood flow regulation. </p>
<p>But what does this have to do with sleepiness? Well, as we’re digesting our meal, more of our blood is shunted to the stomach and gut, to transport away the absorbed newly digested metabolites. This leaves less blood for the rest of the body and can cause some people to feel a bit “light-headed” or tired. </p>
<p>Still, the body is a lot more sophisticated than that; it doesn’t respond to food volume alone. What you eat is just as important as the size of your meal. </p>
<h2>Biochemistry and sleep</h2>
<p>For many years now, researchers have been investigating the link between food and sleepiness, but from another perspective. If we understand more about people’s sleep patterns, we might gain insight into what causes some people to put on weight and develop diseases such diabetes and atherosclerosis (a disease of the arteries that develops with fat deposits in artery walls). </p>
<p>We’ve known for many years that meals with an imbalance of nutrients – that are rich in either fats or carbohydrates – are <a href="http://www.ncbi.nlm.nih.gov/pubmed/3310060">associated with feeling sleepy</a>. But this is not the case when nutrients are balanced or the meal is rich in protein. And that leads to the burning question: what is causing this effect? </p>
<p>Scientists in Germany have documented that meals high in carbohydrates that also have a high glycaemic index (meaning they release sugar into the bloodstream quickly) cause an increase in the hormone insulin. Insulin promotes the absorption and use of glucose from the bloodstream after a meal. But it also allows the entry of a special amino acid (we get these from the digestion of proteins), called tryptophan, into the brain. </p>
<p>This is important as tryptophan is converted into another chemical in the brain called serotonin, a signalling chemical or neurotransmitter that <a href="http://www.ncbi.nlm.nih.gov/pubmed/21641703">can be associated with calmness and drowsiness</a>, especially in children. </p>
<p>But does eating foods rich in the essential amino acid tryptophan, such as turkey meat, cottage cheese, tofu and bananas, automatically make you sleepy? Probably not, as it’s the insulin surge brought about by ingesting carbohydrates that will allow the tryptophan to enter your brain, along with some other amino acids.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/95311/original/image-20150918-12351-lkp6rg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/95311/original/image-20150918-12351-lkp6rg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/95311/original/image-20150918-12351-lkp6rg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/95311/original/image-20150918-12351-lkp6rg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/95311/original/image-20150918-12351-lkp6rg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/95311/original/image-20150918-12351-lkp6rg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/95311/original/image-20150918-12351-lkp6rg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An imbalance of nutrients – meals that are rich in either fats or carbohydrates – are associated with feeling sleepy.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/robbert_michel/3595395786/">Robbert Michel/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
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</figure>
<p>Consuming a high-protein meal, on the other hand, will cause a lot of amino acids to enter the brain and will probably have a stimulant effect rather than a soporific one as the insulin released after eating stimulates their transport across cell membranes. </p>
<p>Cow’s milk drunk warm, often in the evening, for instance, is associated with sleepiness. But it’s the melatonin (a natural hormone that regulates our night or day rhythm) in the milk that can make us sleepy. </p>
<p>First identified in the 1950s, melatonin is a hormone secreted by the pineal gland under the brain. It’s mostly secreted at night, peaking around three or four in the morning. Melatonin acts on receptors in a part of the brain called the suprachiasmic nucleus (a cluster of cells) that triggers sleepiness as part of our sleep-wake cycle. Interestingly, melatonin is <a href="http://www.ncbi.nlm.nih.gov/pubmed/22652369">found in greater amounts</a> in the milk of cows milked in night-time darkness, as opposed to in the daytime. </p>
<h2>Sleep recipes</h2>
<p>So overall, where are we now with our understanding of how food influences sleep? The short answer is that it’s complicated and we don’t yet fully understand it. </p>
<p>We know the gut hormones called enterogastrones, which are released when we eat, can influence blood flow. And that some of these hormones (especially one called CCK or cholecystokinin) can directly make us sleepy, probably by influencing the production of the neurotransmitter serotonin and melatonin. </p>
<p>We also know carbohydrates can promote the release of insulin after a meal, which may promote the actions of tryptophan on the brain, again via serotonin.</p>
<p>But to more practical matters: what should you do to avoid nodding off after a meal? </p>
<p>Here are a few suggestions: </p>
<ol>
<li><p>Don’t overeat; watch your portion size. Allow time during your meal for the level of your body’s natural hormones leptin (which reduces hunger) to rise and ghrelin (normally only released when we initiate eating) to fall, thereby lowering your appetite and inducing a feeling of satiety. </p></li>
<li><p>Balance your meal; have protein and carbohydrate in roughly a one-to-two proportion. Include plant-based or marine-based fats rather than animal-based saturated fats in your meal. And don’t neglect any of the major food groups (vegetables and legumes, fruit, grains, lean meats and dairy products), as they all contain some essential nutrients that our bodies cannot manufacture. </p></li>
<li><p>In particular, ensure you are getting all the minerals and micronutrients you need by including a variety of vegetables or salads in your diet, and a modest amount of fruit. </p></li>
<li><p>Avoid “veging out” after the main meal of the day. Once the meal has settled, be moderately active. This will help promote better blood sugar control. </p></li>
</ol>
<p>Good eating.</p><img src="https://counter.theconversation.com/content/44355/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Angus Stewart does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>We’ve all done it: enjoyed a delicious meal only to nod-off in a comfy chair for a while. A habit for some but unavoidable for others, what is it about food that can make us so sleepy?Angus Stewart, Senior Lecturer in Nutrition and Dietetics, Edith Cowan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/194762013-10-24T19:44:18Z2013-10-24T19:44:18ZFructose health claims ignores evidence of harm<figure><img src="https://images.theconversation.com/files/33670/original/fx56xf3s-1382586428.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The European food agency has decided to allow health claims for products containing fructose.</span> <span class="attribution"><span class="source">Broken Haiku/Flickr</span></span></figcaption></figure><p>The European Food and Safety Agency (EFSA) has just approved health claims for fructose-sweetened products, in a move that has <a href="http://www.theguardian.com/society/2013/oct/17/obesity-experts-appalled-eu-fructose-health-claim-approval">astonished scientists around the world</a>.</p>
<p>Food and drink manufacturers can now claim that their products are healthier if they replace at least 30% of their glucose or sucrose with fructose.</p>
<p>The rationale provided by the EFSA for the decision is that fructose has a low glycemic index (GI). The glycemic index of a particular food is a measure of the rise in blood glucose levels in response to 50 grams of carbohydrate in that food. </p>
<p>This glucose response drives the subsequent insulin response, and insulin is the major hormone driving fat accumulation. That’s the link with obesity.</p>
<p>But it’s not really as simple as that. Just because a food has a low glycemic index doesn’t mean it’s healthy or that you can eat as much of it as you want.</p>
<p>Processed foods containing fat (such as ice-cream, chocolate, and potato crisps) have a low glycemic index because fat slows gastric emptying (the rate at which food enters the small intestine from the stomach). But most of us would recognise they are not the ideal foods to eat when you want to lose weight.</p>
<p>Fructose has a low glycemic index, which is not surprising since it’s not glucose (recall that glycemic index measures the rise in blood glucose levels). But that doesn’t mean it’s not potentially problematic.</p>
<p>Fructose and glucose are handled very differently by the body. Whereas glucose is used by most tissues as a source of energy, fructose is taken up almost entirely by the liver. </p>
<p>When we are eating more than we need, fructose is converted very efficiently by the liver into fat. Just like excessive alcohol consumption, this can cause fatty liver (non-alcoholic fatty liver), which is now very common among people who are overweight and obese. </p>
<p>Left unchecked, fatty liver can lead to cirrhosis and liver failure. It also contributes to weight gain generally. </p>
<p>Excess consumption of glucose (in the form of starchy foods) can certainly contribute to weight gain, but not fatty liver. </p>
<p>Excessive consumption of fructose (more so than glucose) exacerbates insulin resistance and the metabolic syndrome – and thereby greatly increases the risk of type 2 diabetes and cardiovascular disease.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/33672/original/pqdb9d6t-1382587851.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/33672/original/pqdb9d6t-1382587851.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=430&fit=crop&dpr=1 600w, https://images.theconversation.com/files/33672/original/pqdb9d6t-1382587851.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=430&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/33672/original/pqdb9d6t-1382587851.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=430&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/33672/original/pqdb9d6t-1382587851.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=540&fit=crop&dpr=1 754w, https://images.theconversation.com/files/33672/original/pqdb9d6t-1382587851.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=540&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/33672/original/pqdb9d6t-1382587851.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=540&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Ice-cream’s low glycemic index doesn’t make it a healthy product.</span>
<span class="attribution"><span class="source">Cascadian Farm/Flickr</span></span>
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</figure>
<p>It’s important to note that dietary fructose is not a problem if you’re lean and fit, and not over-eating. Under those circumstances, the fructose will be metabolised as an energy source.</p>
<p>The major sources of glucose are starches (polymers of glucose) and sucrose (which is comprised of one molecule of glucose and one of fructose). </p>
<p>Our major source of fructose in Australia is sucrose. In the United States, high fructose corn syrup is now a major source. </p>
<p>While there’s also fructose in fruit, it’s in a diluted form and present with a range of other healthy nutrients and fibre. And health claims are overwhelming applied to highly-processed foods (think of the last time you saw a health claim on an apple). </p>
<p>But why would the processed food industry want to be able to make health claims for fructose?</p>
<p>Fructose is much sweeter than glucose and significantly sweeter than sucrose. The food industry has conducted very sophisticated research on what stimulates food consumption (the “bliss point”), and found that, together with fat and salt, sweetness is one of the <a href="http://michaelmossbooks.com/">major drivers of excess food intake</a>.</p>
<p>So, sweetness is very good for business.</p>
<p>And interestingly, when we drink calories, particularly watery calories as in soft drinks or alcohol (as opposed to soup), our body does not recognise them as such; it’s as if we were drinking water. </p>
<p>Caloric drinks are particularly problematic because <a href="http://www.ncbi.nlm.nih.gov/pubmed/10878689">they’re added on</a> to what we voluntarily eat. </p>
<p>The European Union’s approach to food regulation, then, is very reductionist. The EFSA has taken one short-term impact of a food component (the glycemic index) to justify a health claim for fructose, and ignored all the science that indicates its adverse impacts on long-term health in relation to over-consumption, weight gain, diabetes, heart disease and liver disease.</p>
<p>This is yet another victory for the powerful processed food and beverage lobbies over advocates for public health.</p><img src="https://counter.theconversation.com/content/19476/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kerin O'Dea receives funding from the National Health and Medical Research Council and the Australian Research Council.
</span></em></p>The European Food and Safety Agency (EFSA) has just approved health claims for fructose-sweetened products, in a move that has astonished scientists around the world. Food and drink manufacturers can now…Kerin O'Dea, Professor of Population Health and Nutrition, University of South AustraliaLicensed as Creative Commons – attribution, no derivatives.