This thread has been going for over a year and is a very interesting topic. There is no wrong answer, as different things cause obesity for different people. There are many medications that can cause weight gain. Family history has a lot do do with it, maybe not genetically, but if a child grows up in a family with a lot of obesity, they tend to follow that trend, too. The parents provide the type and amount of food. If the parents do a lot of snacking on salty snacks and sweets, the kids tend to, also. My family ate poorly. We didn't have a lot of snacks, but we ate a lot of carbs and fried foods because they were cheap and filled everyone up. I was not a fat child because I ran around playing outside and burned it all off. When I became a young adult, I didn't want to be fat. When I went out on my own I ate differently and exercised regularly to prevent weight gain. I was not naturally thin. I knew it was not going to happen without some effort from me. When I got married my lifestyle changed and my good eating habits and exercise went by the wayside and I am now obese. So, it was my fault. I could blame my husband, as he might have influenced me to eat poorly, but he didn't put the food in my mouth. I knew the processed foods weren't good for me but I ate them anyone. I knew I shouldn't be going back for second helpings. No one forced me. I had choices and I made the wrong ones. I can be around a roomful of smokers and still choose not to smoke. The same with alcohol. I can drink ginger ale while everyone else is having wine or beer. It's the same with food. It's up to me to eat the choices and quantities that are beneficial to me. I didn't get fat because some farmer injected his cattle with hormones or sprayed his crops with pesticides, not that I think it's OK. I got fat because I put more food in my mouth than I needed.