Risk of eating disorders among vegan diet followers is low, study suggests

Motivated by a desire to control their weight or live a healthier life, large numbers of people display behavior, thoughts or feelings about food and the body referred to by specialists as “dysfunctional dietary behavior” or “disordered eating attitudes”, a risk factor for the development of eating disorders. They include people who start a restrictive diet on impulse, fast for long periods, indulge in binge eating or feel guilty when they eat certain foods. 

A group of researchers at the University of São Paulo (USP) in Brazil set out to investigate the prevalence of dysfunctional dietary behavior among practitioners of vegan diets, which have become popular in this sustainability-conscious age.

According to the article on their research published in the journal JAMA Network Open, they identified “disordered eating attitudes” among only 0.6% of almost 1,000 participants, or less than a tenth of the estimated proportion of the Brazilian population (6.5%).

The authors explain that they wanted to understand the motivations behind adhering to a vegan diet, and to identify any disordered eating attitudes among individuals who do so. A hypothesis raised in the literature is that veganism could be used to legitimize rejection of certain foods and social situations that involve eating. In this sense, it may mask dysfunctional dietary behavior and even eating disorders by facilitating restriction.

“However, the results of the study absolve veganism of blame by showing that the presence of dysfunctional dietary behavior is mainly associated with the reasons for dieting, rather than the type of diet,” said Hamilton Roschel, a professor at the Medical School (FM-USP) and head of the Applied Physiology and Nutrition Research Group.

According to Roschel, the fact that 62% of the participants said their motivation for following a vegan diet was “ethics and animal rights”, whereas only 10% cited “health reasons”, helps explain the low prevalence of dysfunctional dietary behavior in the study sample. “Understanding motivations for choosing a diet and the reasons for patients’ dietary choices helps us design more focused and effective nutritional care programs,” he said.

Methodology

The researchers used an online questionnaire to collect socio-demographic data (such as education, income and location, among others) and information on eating habits for 971 subjects aged 18 or older from all parts of Brazil. By analyzing the data, they were able to arrive at the percentage of vegan diet followers reporting dysfunctional dietary behavior and therefore at risk for the development of eating disorders.

A second stage focused on the reasons for dietary choices. The most frequently cited were “necessity and hunger”, “enjoyment”, “health”, “habits”, and “natural concerns”. The lowest-ranking reasons were “emotional control”, “social norms”, and “social image”.

“Of course, nutritional adequacy and possible deficiencies in restrictive diets should also be analyzed, but as far as mental health is concerned it’s clear that what matters most is understanding why individuals make their particular choices, monitoring their status, and if necessary referring them to a suitable specialist,” Roschel said. “In addition, our findings can help design public interventions to promote healthy eating and prevent or treat eating disorders.”

More research is required, he added, involving more heterogeneous probabilistic samples and qualitative analysis. The study in question cannot be used to infer causality, he acknowledged.

The study was funded by FAPESP via five projects (19/14820-6, 19/14819-8, 20/07860-9, 22/02229-4 and 17/13552-2). 

The investigation was conducted by the Applied Physiology and Nutrition Research Group, comprising scientists affiliated with FM-USP and the School of Physical Education and Sports (EEFE-USP). The principal investigators were Bruna Caruso Mazzolani and Fabiana Infante Smaira. Bruno Gualano, Gabriel P. Esteves, Martin Hindermann Santini, Alice Erwig Leitão and Heloísa Santo André also collaborated.