Roberts, R.E., W.J. Strawbridge, S. Deleger, and George A. Kaplan. 2002. "Are the Fat More Jolly?" Annals of Behavioral Medicine, 24(3): 169-180.
Does obesity affect mental health? Two waves of data from a panel study of community residents 50 years and older were used to investigate the association between obesity and eight indicators of mental health: happiness, perceived mental health, life satisfaction, positive affect, negative affect, optimism, feeling loved and cared for and depression. For none of the eight mental health outcomes examined did we observe a protective effect for obesity. Either no association was observed between obesity and psychological functioning, or the obese were worse off. Using 1994-1999 prospective data, the obese were at increased risk for poorer mental health on five of the outcomes examined using bivariate analyses. However controlling for mental health problems at baseline and using statistical controls for covariates, the increased relative risk was limited to depression. There has been sufficient disparity of results thus far to justify further research on this question.