Quite often it's really a question of gut flora and lack of knowledge regarding good eating habits.

Also fat cells are endocrinologically active, so they try to compel the person to, well, get fatter.

I've been doing this the hard way lately and there's still much that I don't know, because food and lifestyles used to be different, so my parents only told me what they knew from theirs.

To illustrate just how different, my great-grandmother reportedly disliked food that she described as "rich" - too calorie dense for her taste. By this definition cottage cheese was "rich".

I doubt it. I've never been overweight in my lifetime. I have never had to put any effort into that. I simply cannot relate at all to the food-related struggles I sometimes read about overweight people having. It would be silly and condescending of me to claim that I simply have more strength of will here than they do. On the other hand, I struggle heavily with some things many/most people do not, and this is often blamed as a personal failure and weakness of mine. So I wonder if it's just that people who don't have any similar struggles think they are just superior beings with superior willpower.