Yeah the genetics did it, not the 12 Big Macs for snacktime before dinner.
You mean sarcasm but the diet of a fatty and a thin one might be very similar. From memory, I had the opposite problem as a kid. I was a beanpole who didn’t gain an ounce and mom tried such things as feeding me lots of high fat food to no avail. Now I wish I had that problem, as adult years suddenly saw a great fattening of my waistline.
Do you have a source for that claim?