Research suggests that weight loss treatment generally benefits psychological well-being but these effects have never been quantitatively reviewed. A meta-analysis of 117 weight loss treatment tests showed that weight loss treatment was associated with lowered depression and increased self-esteem. Treatment type moderated treatment effects on depression and self-esteem. Actual weight loss moderated treatment effects on self-esteem but not depression; only treatments that produced actual weight loss predicted increased self-esteem whereas improvements in depression were independent of weight loss. The clinical implications of the findings and the possible causal relationships among weight, depression and self-esteem are discussed.