Millions of Americans are overweight or obese. Medication and psychotherapy may result in modest weight loss but nearly all regain weight within five years. The missing ingredient for successful treatment is cognition. To make permanent changes in their eating behavior, and thus their weight, individuals must learn how to change their dysfunctional ideas about food, eating, other people, and themselves and learn how to cope with a sense of unfairness, deprivation, disappointment, and discouragement. Cognitive behavioral approaches have been demonstrated to be effective for this problem.