Childhood obesity: the end of an epidemic?

The battle isn’t over yet.

Children in Canada, their parents, health professionals and government ministers will welcome the news that there has been a decline in overweight and obese children over the past ten years. Although there is a long way to go before levels of childhood obesity return to the levels seen in the 1980s, the reduction in the proportion of children in Canada who are overweight or obese is a rare achievement.

Childhood obesity is recognised by the World Health Organisation as one of the most serious public health challenges of the 21st century. Adult obesity is linked to cardiovascular disease (heart disease and stroke), cancer, diabetes, osteoarthritis and chronic kidney disease. It is also associated with reduced life expectancy and reduced healthy-life expectancy. Children who are obese are likely to become obese adults and so are at risk of these health problems.

But childhood obesity isn’t only a health risk because of its association with adult obesity. Childhood obesity itself is associated with premature mortality, early onset type-2 diabetes and cardiovascular risk factors such as hypertension (high blood pressure) and high cholesterol. It is also linked to asthma, musculoskeletal problems (such as arthritis), and psychological problems. Children who are obese have worse general health and more school absences as a result, which may have consequences for them beyond health.

Obesity can also cause musculoskeletal problems.

Improvement, but not enough

In this latest study, the decline in childhood overweight or obesity was found in data on 14,014 children and adolescents aged three to 19 years at three time points: 2004-2005, 2009-2011 and 2012-2013. The percentage of children who were overweight or obese was about 31% in 2004-2005 and fell to 27% in 2012-2013. The percentage of children who were obese remained stable at about 13% over the whole time period.

Globally, prevalence of overweight and obesity combined has risen by 28% for adults and 47% for children between 1980 and 2013. In developed countries, there has been a dramatic increase in the prevalence of childhood obesity and overweight. This has risen from about 17% of boys and 16% of girls in 1980 to 24% of boys and 23% of girls in 2013. This means an extra two children in every class of 30 are overweight or obese now, compared with 30 years ago.

The prevalence of overweight and obesity is also rising among children in developing countries, increasing from 8% in 1980 to 13% in 2013. This average figure hides a large variation. Over 30% of girls in Kiribati, Samoa, and the Federated States of Micronesia are either overweight or obese, but less than 2% in other countries including Bangladesh, Cambodia, Ethiopia and Tanzania.

There are a few developed countries that have reported small declines or a levelling out of their childhood obesity rates, similar to what is being reported now in Canada. These countries include Poland, Australia, the Netherlands, Germany and Denmark.

In the UK, there was excitement when annual Health Survey for England data suggested that childhood obesity had stopped rising – indeed, the reported figure for 2010 was the lowest recorded since 2001. This was credited to sustained focus on childhood obesity by the Labour government.

Specifically, a number of initiatives were introduced including the National Child Measurement Programme, which promoted recognition by families of their own children’s weight status and Change4Life, a government public health social marketing campaign, which was particularly directed at families of young children. There were also restrictions put in place on marketing junk food, high in salt, fat and sugar, to children. But, in 2014, obesity among boys aged two to 15 years rose back to the peak level of 19%, previously recorded in 2004. Levels of overweight and obesity were at 32% for boys and 31% for girls, creeping towards the peak of 35% seen in boys in 2005 and girls in 2004.

Given what has happened in England, it may be too early to celebrate the Canadian data. In particular, it is worth noting that the levels of overweight and obesity combined have fallen, but that levels of obesity have remained high. Those children who are obese are most at risk of the associated health problems, so while reducing the percentage who are overweight is a good start, until the percentage who are obese is also falling, it may not make as much of a meaningful difference to the generation’s future health and well-being.

No time to rest on laurels

Obesity has environmental, psychological and biological causes. It is a complex health issue which requires action on many levels if we’re ever going to address it successfully. The situation in Canada suggests it is possible to stop the relentless rise in childhood obesity and this should motivate us to continue to pursue the more ambitious aim of a continuous decline in childhood obesity back to 1980 levels, or lower.

The World Health Organisation’s Commission on Ending Childhood Obesity was established in 2014. It has made a set of recommendations for how to successfully tackle childhood and adolescent obesity in different contexts around the world. Implementing these recommendations requires government action, and this is more likely when it remains an issue that the public care about. The childhood obesity epidemic isn’t over yet and we must continue to be passionate about ending it.