Research appearing in the Proceedings of the National Academy of Sciences (Sept 30, 2003; vol. 100; no. 20; 11696-11701) shows why stress creates craving for comfort foods. The study looked at corticosterone production in rats (the equivalent human hormone is the adrenal hormone cortisol).  Stress causes an increase in corticosterone in rats. The hormone prompts pleasure seeking behavior—including eating high energy foods like sugar and lard.

Eating those comfort foods may actually work to control the hormonal output of stress. When chronic stress is present. “Our studies suggest that comfort food applies the brakes on a key element of chronic stress,” says study co-author Norman Pecoraro, PhD. It makes sense, high energy food is likely to be needed in times of acute stress.

In areas where there is war, epidemic, hunger and other extreme stressors, there is a need for high energy food. Such food can help with survival. In comfortable civilization, there is chronic stress—and comfort foods are everywhere. An increase in abdominal fat, actually reduces the production of the stress hormones. “This seems to be the body’s way of telling the brain, ‘It’s ok, you can relax, you’re refueled with high-energy food,'” says Pecoraro. This can explain the difficulty many people have with losing weight. Weight loss is stressful, causing the output of adrenal hormones and the desire for comfort foods.