Obesity is not hereditary, it has a lot to do with diet.  I discovered this through family history in part.  And honestly, it’s a bit funny.  My family members with the exception of one have never actually blamed it on heredity, they know better, they see better.  My ex aunt is the one that does.  And her mother has a belly now, only because frankly she’s about 80 years old and has gained weight over time.  But frankly, she has never been a particularly big lady.  She’s just about average.  On the other hand, my ex aunt is literally about 400 pounds.  Likewise, my great grandma was always a bean pole as was my great grandpa.  My grandpa is a bean pole, and my grandma since her younger days is a short lady, under 5’, which keeps her weight lower.  But still, she’s about 200 pounds.  It’s because she’s always eating these cheese sandwiches, she made us caramel popcorn whenever we were over.  As she got older, we started cooking for ourselves, and she cried because she thought we no longer liked her cooking.  We were doing it, because she really developed some serious health problems, a lot of them obesity related and frankly we didn’t want her to feel that pressure to always take care of us.  She always took care of us as kids and spoiled us rotten, which is what a grandma really should do.  But as we got older, we figured we should take care of her.  After that, we went back to allowing her to do some things.  We would make caramel popcorn again and tell her how much we loved it all the time.  But we would change it so we were actually following her recipe and just doing a lot of the work for her, which really helped to take the pressure off while not making her feel bad.  She is like some cultures where they express their love through food.  But honestly, it’s never been about heredity.