We examine the principal features of dieting using an evolutionary perspective, which sheds light on certain anomalies while raising other interesting questions. We focus on (a) the reasons that dieters give for dieting, (b) the difficulty of dieting, and (c) the apparent opposition between the proclivities toward self-indulgence and self-control. We propose that while self-indulgence and self-control both serve adaptive functions, these evolved tendencies are naturally triggered by different ecological challenges. Implications for dieting in an ecology of plenty are explored.