Earlier quoted context omitted.
It's not a direct link though. I can stuff my face with nothing but donuts for weeks on end and never put on an ounce of weight. Which is probably as irritating as someone who can't lose weight.
It is a direct link because I am talking about calories. There is a myth that there are people who can eat whatever they want and not gain weight. Everyone has a base amount of calories to work from and if you go over that amount you gain weight.
I eat as much as I can, often twice as much an average person - it typical for me to have two helpings in a meal where most people have one.
I have never gone over 145 pounds and I am 6' tall. I cannot gain weight, period. And I'm not alone as other posters mention.