Weight gain is primarily induced by over-eating. That's fact.

- Most post-menopausal women are not obese. Indeed, most do not gain much weight post-menopause. - Drugs, by and large, do not result in weight gain. A few drugs do, but only a few. - Cancer weight loss is a product of the body not being able to digest enough food for the body to use for maintenance, usually because nausea induces vomiting before the food is fully digested. - As for the sugar: the problem boils down to (again) overeating caused by the taste of sugar stimulating a desire to eat more (sugary) food. In the end, overeating is still the problem. - Finally, as for human growth hormore: the effects of premature puberty have been documented in cultures where growth hormone is not present in the cows such as in India and China (among the portions of the population wealthy enough to over-eat). Thus, it is clear that growth hormone has a negligible, or at best minor, effect on obesity.