AbstractPopulation studies provide information on associations between affect, personality and body weight. Anorexia and bulimia are associated with psychiatric disturbance and successful treatment in both is accompanied by affective changes. Depression may be accompanied by either a loss of appetite or an increase, with accompanying weight changes. Anxiety may have similar effects and restraint is an important principle in determining eating responses accompanying these illnesses. Psychotropic drugs that affect mood also affect appetite and these include psychostimulants, antidepressants, antipsychotics and lithium. Obesity is a major problem in the western world and it is logical to consider the roles played in its reduction by psychological and affective changes.