Fruit’s so hot right now, but it can’t deliver a balanced diet alone

Summer means fruit. Some varieties as appetising as melon, watermelon, peaches and strawberries are in season. And hot temperatures can put us in the mood for light and fresh meals. Indeed visitors from cooler areas to sunny climes, such as Spain, might be tempted to “fruit binge”, cutting back on other foodstuffs. That can be a dangerous route to go down. There are also a few tall tales about fruit. So, when better to tackle them? I work the field of vegetal biotechnology and research the cellular and molecular biology of plants. I have also written the book What is eating healthy? – fruit is a profession as well as passion for me.

Mix it up, and cook

Although fruits are very healthy food items, which provide many nutrients and few calories, it is too complicated, if not impossible, to have a balanced diet based solely on fruits. If we tried to do this, we’d miss out on certain nutrients such as vitamin B12.

We hear much about vegetarianism and vegan diets but there are also followers of fruitarianism or frugivorism, who only eat parts of plants that do not involve killing it. They mainly consume fruits and cereals. This makes for a very poor diet that could cause health risks.

In addition, when food is cooked, the availability to consumers of different nutrients increases. Anthropologist Richard Wrangham points out that man is different from other animals in this regard due to our ability to cook the food, which allows us to get better use and energy from it. Gorillas are raw vegans, but spend most of their time eating and digesting, and need to eat a much larger amount of food than we do. In short: eating fruit is fine, but it’s not a good idea to only eat fruit.

When’s fruit o’clock?

One of the myths that we most commonly hear is that, if we eat fruit before meals, it is easier for us to digest and it is less fattening. This is not true at all. Our stomach digests as food reaches it, and it doesn’t matter what order we eat things in: everything ends up being broken down so that our intestine can absorb the nutrients.

Myth of the midnight killer melon

In Spain there is a popular saying which goes: “Melon in the morning is gold, in the afternoon it’s silver, and at night it kills you.” Who would have thought that popular wisdom is not always true. In summer, melon is a good option at any time of the day, and it’s better to have two slices of this fruit than a Pantagruelian banquet.

This myth seems to date back to the Middle Ages, when melons were so expensive that they were reserved for the elite. Biting into a melon was the ultimate status symbol. It has been suggested that the emperor of Austria, Albert II, in 1358 and popes Paul II in 1471 and Clement VIII in 1605, died after feasting on melons, which may have given rise to the myth. Proof of just how appreciated they were is that, as late as the nineteenth century, the writer Alexander Dumas ceded his library to the city of Cavaillon, in Provence, in exchange for the annual delivery of 12 melons until his death.

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Beyond just juice

It sometimes feels appetising to have a fruit juice rather than fruit, but we must remember that this not equivalent. It’s simple: if we eat an orange for dessert or snack, we usually stop at one. But if we make an orange juice, we’ll use four or five. And that means more sugar is consumed.

The other big benefit of fruit, rather than just fruit juice, is fibre. Juice is good for you, but extracting it means losing much of the nutritional value of the rest of the plant. So it’s better on two fronts to eat one piece of fruit than to extract the juice of a punnet and slurp it.

There is also no such thing as detoxifying juices, in spite of the fact that some marketing suggests we accumulate toxins, and that we can get rid of them with a diet based heavily on juices. Intoxication requires medical attention, not a smoothie.

So, as a researcher working on the biotechnology of plants, and a fruit lover, I can say with confidence, go forth and enjoy a wide range of fruit this summer. But, as ever, do so as part of a balanced diet. No matter how good it tastes, fruit alone will not delivery a healthy lifestyle.

This article was originally published in Spanish