AN ESSENTIAL ELEMENT: Interest in psychological factors of obesity has been clearly on the decline over the last thirty years. Despite this fact, the psychological approach to obese subjects is a fundamental element both in understanding the causal mechanisms but also to follow therapeutic effects in the long run. However, everything cannot be explained by the fact that many nutritionists lack a formation in psychology and many psychiatrists lack interest for corporal diseases. What is missing is a theoretical background allowing each participant to find his/her role in this multifactorial condition which requires a multidisciplinary management. COLLABORATIVE CARE: The nutritionist-psychiatrist pair would appear to be the best choice for a large number of obese subjects who may or may not have eating habit disorders. The type of psychological help will depend on many factors: the subject's background, environment, demands, and most importantly, capacity for mentalization. There are many possibilities for simple supportive care: psychoanalytic approach, behavioral therapy, cognitive therapy, etc. The choice of a therapeutic method depends on the clinician's competence and on the subject's characteristics. An emphatic active attitude is indispensable for those patients whose demand for psychological help is often buried in the somatic condition.