Eh, then how come America has become more fat in the last 30 years? Do the genes degenerate that fast? The article is so bad that I suspect the author is trying to score with a fat chick and published this to make her feel better or something;-)
"Although our high-calorie, sedentary lifestyle contributes to the approximately 10-pound average weight gain of Americans compared to the recent past, some people are more severely affected by this lifestyle than others. That's because they have inherited genes that increase their predisposition for accumulating body fat. Our modern lifestyle is thus a necessary, but not a sufficient, condition for the high prevalence of obesity in our population."
Which basically gives you the answer to your comment. You've read the article, haven't you?