Not quite true. Fat mothers give birth to babies that are more prone to obesity than the offspring of a human mother. https://www.sciencedaily.com/releases/2016/08/160822155938.htm That's not to say that there's any gene that will override the fundamental laws of thermodynamics. It's still a matter of eat less, lose weight. Problem is, the spawn of fats will have more trouble than they should maintaining a healthy weight. Add to that the effects of being raised in the "fat lifestyle" of endless chewing and a social environment in which calling someone fat (or even implying it) is on par with espousing admiration for the Third Reich, you've got a recipe for multi-generational fats.