The starvation response is a series of changes the body undergoes when there is a lack (or significant reduction) in food, in order to prevent entering full "starvation" which is the completely lack of fat to generate the sugars required by the brain where the body will finally switch to the use of protein(your muscles and organs) as the source of the necessary sugars to keep you alive. When someone eats a significantly reduced calorie diet, they live on the edge of initiating the starvation response, whereby they have a reduction in metabolic rate as well as burning their free fatty acids. Because they irregularly have an intake of high calories, this tends to generate excess fat, while not burning fat. Even more so due to the decreases in the metabolic rate. The net result is that a person who, overall, is eating less calories than the basal rate, will maintain or even gain weight.

Not only is it fact, but it is exactly the reason that Doctor's tell you to eat more food when you are working out and trying to lose weight. Get too far below on even a semi-regular basis and the result is that you not only stay the same, but often gain, even with all the calories you are burning. Sources? Doctors who specialize in metabolism and who actually know what they are talking about. Otherwise, find them yourself instead of repeating what you heard from someone, who heard it from someone, who read it on a blog from someone who heard it from someone else.

Fat people can be lazy, just like skinny people, but saying "eat less" is the solution is just ignorance, because thats often not how it works. "Eat less" often gets interpreted as "eat almost nothing" by fat people, which makes things even worse, and it's jackasses like you that help cause that problem.