The overlooked factor driving the childhood obesity crisis

There has been no extensive research in Britain on why school absence might be causing obesity, but doctors who have spoken to the BBC have their theories.

One factor is diet. Since the 2000s – when all four UK governments passed laws to make school lunches healthier – it’s become much harder to find high-sugar or high-fat foods in most canteens. At home, those restrictions don’t apply. By 2010, a few years after the new laws were introduced, a study from the University of Leeds found that only 1.1% of home-packed lunches met the nutritional requirements that would apply to a meal bought by a child at school.

And a US study from earlier this year found that child obesity rose in states where a universal free school meal programme was withdrawn in 2022 (presumably because it prompted children to eat unhealthy food at home).

“While school food is not as good as it should be, there are some regulations around it,” says Keith Godfrey, an epidemiology professor at the University of Southampton. “Whereas in the home environment, it’s much more variable in terms of what children receive.”

Exercise also matters. A British study from 2014 looked at step counts measured with electronic sensors, and found that most children are more active on school days than weekends.