A while ago I saw this TED talk about the futility of dieting. The speaker suggests that a body maintains a homeostatic weight point and returns to that weight after dieting has stopped:
Turns out the brain is an incredibly efficient regulator of body weight. Isn’t weight loss about how much you eat versus how much energy you burn? Nope, it’s not that simple an equation: it turns out that hunger and energy use are controlled by the brain, mostly behind the scenes, and this unconscious force is stronger than mere willpower. The brain has its own sense of what your body should weigh — no matter what you believe — called the set point, which has a range of about 15 pounds. While lifestyle changes can shift your weight within this range, it’s much harder to move outside of it.
The speaker suggests that once she gave up dieting, she actually lost weight. Since then I've seen a number of other anecdotal reports of people losing weight once they let go of the need to diet and started to "eat anything they wanted".
This makes me ask - does anxiety about weight and attempts to control one's eating cause people to put on weight? In other words, if there's some unresolved anxiety issue in one's life, does it cause the human body to start preparing for hard times by storing extra fat?