Lack of proper diet growing up, lack of information, misinformation, general apathy, undiagnosed endocrine disorders that make it difficult to lose weight (and, thus, the individual becomes easily discouraged), unrealistic goals force upon a person by peers. A person can be obese for any number of reasons - not all of them being the person's fault.
A large part of childhood obesity lies on the parents. If Pa and Ma aren't teaching dear Johnny to get sixty minutes of exercise a day and cooking him healthy meals, how's he supposed to understand that stuff at a later age? The non-existent nutrition classes offered by his school? By the time the person's an adult they have a very large amount of work to do to get to a place they've never been.
Obese individuals cannot operate at the same level as you or I could. Their joints have far more pressure and asking someone who weighs quite a bit to, say, do the same exercise as yourself is more than likely going to hurt this overweight individual. Your partner's parents were likely just as much to blame for his issue as he was. He didn't just decide at age six to be fat and never exercise and eat a $0.99 cheeseburger.
Never mind the exercise and dieting industry making people feel like failures for not getting instant results. Have you ever walked down a diet isle at a grocery store? Ten day miracle cleanses! Meal replacement bars! Alli! Six week abs! Turn fat into muscle! Weeeee!
Even the non-commercial things lie. I bet even you, as a former athlete, have completely incorrect notions of some form of exercise or fitness. Women often have this notion that weightlifting will get them 'bulky' and, thus, they stick to cardio. You as a former athlete should know how difficult it is for a male to get bulked, never mind a woman.
Obesity bothers me because it's a completely preventable disease in most cases. There are people who have disorders. They will have to work a hundred times harder than you ever will while on medication to even maintain a healthy weight. It truly sucks to be them. However, the rest of us have no excuse beyond laziness.
[sub]Why yes I've been researching this topic what are you talking about.[/sub]
Edit: FORGOT GENETICS GOSH DANG IT. :I
