Men who were overweight in all age groups (seven, thirteen, and early adulthood) were four times more likely to develop type 2 diabetes between the age of 30 and 60, and this risk was the same for men who were of a normal weight at seven but had become overweight by the age of thirteen and after, compared with men who were normal weight at all ages.
For men who had only put on weight by the time they hit early adulthood, the risk was three times higher.
Read More: Diabetes is more fatal for the poor
Even small changes in BMI count
Reducing BMI between the age of seven and eighteen was associated with a reduced risk of developing type 2 diabetes.
Even boys with obesity could halve their risk by reducing their BMI from ‘obesity’ to ‘overweight,’ and they could remove the elevated risk entirely by bringing their BMI down to a normal level.
In contrast, every single increase in BMI was associated with an increased risk of type 2 diabetes.
In general, there was an increased risk of type 2 diabetes among less educated eighteen-year-olds. But this could not explain the increased risk observed in men with overweight. And regardless of educational level, they could all reduce their risk of developing type 2 diabetes by losing weight before puberty.
Read More: Birth weight linked to diabetes and obesity
We need to prioritise prevention of overweight in children
All in all, our results show that overweight around the age of puberty indicates a pattern of weight gain, which is particularly significant for the risk of developing type 2 diabetes.