There was an article on HN the other day showing that after you gain weight and lose it, it's difficult to keep it off because you don't feel full easily and feel hungry more often. So if you were fat as a kid, you're at a huge disadvantage later on in life.
It's "easy" to live on a SW engineering salary where you can afford whatever food you want, after being raised by parents that fed you good food and not be fat.
It's much harder when you grew up fat, working a minimum wage job and living in a food desert.