Many different treatments for obesity have proven somewhat successful, with none emerging as clearly superior to the others. Surgical approaches, although usually successful at achieving and maintaining weight loss, are accompanied by varied and often harmful side effects. Unless new, safer procedures are developed, treatment may continue to be as hazardous as the obesity itself. Because medical treatment alone has not achieved beneficial, lasting results, research aimed at finding new procedures should be encouraged. Our five-year experience in working with obese patients has led us to the following conclusions: 1. The management of obesity must be a joint venture between psychiatry and medicine. Because of the complex nature of this illness, neither discipline alone can successfully and safely achieve significant initial weight loss coupled with successful long-term maintenance. The use of adjunctive psychological programs in a medical setting can be a successful alternative. 2. Fasting, weight loss, and realimentation must be accompanied by an effort at lifestyle change. Otherwise, patients will continue their self-destructive habits, which will ultimately lead to failure in yet another attempt at sustained weight reduction. The behavioral approach has provided a fairly effective treatment of obesity, sometimes with immediate results. Recent studies support the maintenance effect of behavioral treatments. However, longer studies with follow-ups are needed to better assess the overall effectiveness of these treatments. 3. Despite much false optimism that weight loss is a simple road to happiness, most patients experience some very real problems during the fasting part of the program. Crisis intervention can prove very helpful in terms of reducing stress and preventing dropouts. Group therapy, individual therapy, family therapy, and hypnosis have attained some very limited positive results when used alone; greater success has been reported from combining therapies. Patients generally became more socially effective, physically active, and mentally proficient when exposed to individual therapy together with group and family therapies. 4. Family environment appears to significantly affect compliance and completion. A conflict-laden family environment hampers the patient's ability to deal with the psychological changes encountered in weight loss programs. 5. Many obese patients lack a fundamental knowledge of nutrition, exercise, and health. In addition, most are poorly socialized and require assistance in learning assertiveness and other interpersonal skills. A behaviorally oriented component is very effective in providing these skills.(ABSTRACT TRUNCATED AT 400 WORDS)