It has long been a contention of mine that the remarkable thing about obesity in childhood is that it goes away much more often than obesity goes away during the rest of adult life. We have been telling pediatricians that they should be preventing obesity since it is so impossible to treat once established. Maybe we can help them by studying what makes it go away spontaneously so often in children. So it was with interest that I read a report about how often this happens, in Chinese kids in school in Hong Kong at least. These investigators also found that one thing that doesn’t seem to cause obesity in kids is a lack of physical fitness. (1)
They examined 18,863 students when they were only 6 to 8 years old and measured their body shape and physical fitness and then checked again after 4 years when they were 10-12. They found the prevalence of obesity at baseline was 5.7 %. After 4 years, the obesity prevalence increased to 6.7 %.
Also, those that were obese at the beginning were 6.5 times more likely to be obese at the end. And if they were overweight but not obese, they were 4 times more likely to be obese by the end of observation. Finally, tracking of obesity shows increasing persistence as kids get older. This is always what is alarmingly stressed in these secular trend studies. But what these authors point out is that only 35% of the kids who were obese at 6-8 years old remained obese after 4 years; whilst among the 3307 students with either overweight and/or obesity at baseline 18 % became obese at follow-up 4 years later. Looking backward, among the 1272 students who were obese at the end, only 386 (30.3 %) had been obese at baseline 4 years earlier.
Furthermore, they found that physical fitness at baseline did not add any positive or negative value to the presence of obesity to help to predict who would be obese at the end.
Rather than scrutinizing kids who are too fat we should be just checking the 60 plus percent who it beat it and see what their trick was and what’s wrong with the ones who don’t start off that way but get obese later. One factor we can maybe cross off so far is exercise.
Tung, Jl., Ho, F.Kw., Tung, K.Ts. et al. Does obesity persist from childhood to adolescence? A 4-year prospective cohort study of chinese students in Hong Kong. BMC Pediatr 21, 60 (2021). https://doi.org/10.1186/s12887-021-02504-7 https://link.springer.com/article/10.1186/s12887-021-02504-7
This writer’s opinion is their own and not the opinion of this newspaper
John DiTraglia M.D. is a Pediatrician in Portsmouth. He can be reached by e-mail- firstname.lastname@example.org or phone-354-6605.