diet-philia means: An inherited disorder that causes one to be sexually stimulated by the thought of a woman trying reduce her size or weight for aesthetic purposes. A woman with an obesity diagnosis will not experience sexual arousal if she attempts to lose weight. However, women who are already slim may feel the need to trim down to enhance their sexual attraction. Her enthusiasm for the possibility of being more sexually attractive, and not self-hate or dread, must also be the motivating factor in her weight loss. (in Community Dictionary, added by RapisWonky)