I'm glad that you linked me to this article because I now know what you are basing your arguements on.
After reading the article, I've concluded several things.
1. The study done in rats shows that there is a genetic influence to obesity. The rats only became obese after adopting unhealthy eating habits. Had they not, they would not have become obese. While the risk for obesity may be greater in other because of genetics, it does not cause obesity.
2. There was a portion in this article that was talking about how when a person loses weight, an obese person, their calorie expenditure is low and their hunger increases, which explains why people go off their diets and gain weight. Regardless of the stress the article had on how ravenous the food cravings are, if the person eats an amount of calories they can burn of obesity will not occur.
The article, basically, was saying the reason people go off their diet has a lot to do with the cravings genetically being harder to ignore than in normal people- but this does NOT cause obesity. Overconsumption of calories that cannot be burned off by the body does. While it is more likely, and easier for certain persons to become obese simply because of these genetics factors, it does NOT create obesity, as was proven by the rats.