Many dieting behaviours can be damaging to physical and psychological health. Fluctuating weight is common for most people who diet frequently, as most people re-gain all the weight they have lost after a diet. Weight loss or weight gain may lead to long-term physical side effects. As well as the physical effects, dieting can be damaging to people's emotional and psychological health, for example, people who diet frequently are more likely to experience depression.

Apart from the associated risks of restricting certain foods in our diet, dieting can lead to eating disorders. Recent research shows that women who diet severely, are eighteen times more likely to develop an eating disorder. Women who diet moderately are five times more likely to develop an eating disorder. Although past dieting is common among people with eating disorders, there are many reasons a person may chose to diet in the first place.