> Some people are simply predisposed to put on fat and retain it. Aesthetically this may not be what they wish for, and that can lead to desperate dieting and more exotic attempts at fat loss.

Can you provide references for this?

I'm not sure about this one. I've read that in reality, most people have the same resting metabolic rate, i.e. we spend roughly the same amount of calories just to live. It's very possible that there are differences in the efficiency of our digestion systems, but I find it unlikely that the differences are that great (apart from specific foods, e.g. milk). So I'd say that most of the "predisposition" is purely mental.