Causes of Obesity

Obesity is a global health concern with the worldwide prevalence more than doubling since 1980. In the UK, childhood obesity is a particular policy concern, with data from the National Child Measurement Programme showing that between 2006/07 and 2013/14:

  • While there was a significant downward trend for obesity, excess- and over-weight in boys and no significant trend for girls entering reception class.
  • By year 6, there was a significant upward trend for both boys and girls in obesity and excess-weight with the trend being highest for girls. There was also a significant upward trend in over-weight among Year 6 girls, but no similar trend for boys.

The findings of this study imply that there is scope for doing more to tackle childhood obesity in school settings between reception class and Year 6. Much of the debate in this area has focused on policies to encourage physical exercise and healthy diets and calls for tighter controls on the way that foods are marketed, advertised and labelled. However, there is evidence implicating a wide range of other factors in obesity. These include ethnicity, the composition of the bacteria found in the gut (the microbiome), environmental exposure to certain types of chemical (so-called obesogens), lack of sleep, stress, maternal age and health and the in utero environment. This POSTnote will examine the evidence base for the links between such factors and obesity and assess its relevance to informing policy.