Associations between vegetarianism, body mass index, and eating disorders/disordered eating behaviours: a systematic review of literature

The vegetarian diet is becoming increasingly popular among the general population and has been accompanied by an increasing number of publications in the last twenty years. However, the spread of selective diets raises some questions, especially with regard to health. This review examines studies on vegetarianism published between 2000 and 2022 that investigated the associations between this diet, weight, and eating disorders. The descriptive studies conclude that vegetarians have a lower body mass index, and the interventional studies show the value of a vegetarian diet for weight loss. While some studies suggest that vegetarianism may be associated with orthorexia nervosa, the results regarding the association between vegetarianism and eating disorders are more heterogeneous and depend on the type of samples and dimensions studied. The heterogeneity of these findings is discussed in light of the methodological limitations of the studies to provide perspectives for future research.

Automated summary

The vegetarian diet has gained popularity in recent years, leading to an increase in related research. This review examines studies published between 2000 and 2022 that explore the relationship between vegetarianism, weight, and eating disorders. Descriptive studies find that vegetarians have a lower BMI, and intervention studies demonstrate the effectiveness of a vegetarian diet for weight loss. However, the association between vegetarianism and eating disorders is more varied and depends on the samples and dimensions studied. The heterogeneity of findings is discussed in light of methodological limitations, providing directions for future research.