Looking at the relationships between participants' body mass index (BMI), as measured eight times during the study period, the FTO variants they had inherited and when they were born revealed that the previously reported association between a specific FTO variant and BMI was seen, on average, only in participants born in later years. While there was no correlation between the obesity-risk variant and BMI for those born before 1942, in participants born after 1942 the correlation was twice as strong as reported in previous studies. While this study was not able to identify the environmental differences that combine with FTO variant to increase the risk of obesity, the authors note that post-World War II factors such as increased reliance on technology rather than physical labor and the availability of high-calorie processed foods are likely contributors.Well a little. The major environmental change was the Surgeon General advising we all eat a Low Fat Diet.
These metabolic effects are triggered by a persistent high carbohydrate intake. Period.