Vegan vegetarian eating disorders link unclear in review

A new review on vegan vegetarian eating disorders found no clear overall difference in symptoms between people who avoided meat or animal products and people who ate meat. The finding matters because clinicians and families often worry that cutting out food groups can mask or accompany disordered eating, while many people choose these diets for ethical, religious, environmental or health reasons.

Bruno Bizzozero Peroni and María Valentina Díaz Goñi wrote in The Conversation that their systematic review and meta-analysis combined 24 studies covering 25,223 participants. The studies used established questionnaires to measure self-reported experiences such as food restriction, loss of control while eating, and distress over weight or body shape.

The researchers said those tools measured symptoms, not clinical diagnoses. They also said the diet label alone did not reveal much about a person’s mental health, because two people can avoid the same foods for very different reasons.

Do vegan and vegetarian diets cause eating disorders?

The review did not show that vegan or vegetarian diets cause eating disorders. The researchers said all 24 studies were cross-sectional, meaning they captured information at one point in time and could not establish whether dietary changes came before eating disorder symptoms or followed them.

A systematic review identifies and assesses the available evidence using a structured method. A meta-analysis pools numerical findings from comparable studies to estimate the overall pattern, according to the authors.

The review used strict diet definitions. Vegetarians were defined as people who excluded meat, poultry, fish and seafood, while vegans were defined as people who excluded all animal-derived foods. The researchers excluded flexitarian, pescatarian and semi-vegetarian diets because those diets permit some meat or fish and may be adopted for different reasons.

Across the individual studies, results differed. Some found more eating disorder symptoms among vegetarians or vegans, some found fewer, and others found no clear difference, according to the review. When the researchers combined the results, they found no meaningful overall gap between the diet groups.

Why motivation matters

The authors said motivation is central to interpreting food avoidance. A person who has long avoided animal products because of concern for animals and remains comfortable around food differs from someone who keeps adding food rules because of fear of weight gain.

Only a small number of studies in the review examined motivation, the researchers said. One study of university students found that people who partly adopted vegetarian diets for weight control reported more eating disorder symptoms, but most studies did not record why participants followed their diets.

Qualitative research involving people with eating disorder experience suggests that clinicians should ask when the diet began, whether fear was involved, whether additional food rules appeared and how much flexibility remains, according to the authors. They said sudden dietary change with weight loss, distress, secrecy or increasing restriction may call for closer attention.

The evidence had several limits. The researchers said the studies included limited information about diet quality, how long participants had followed their diets and why they adopted them. Most studies were conducted in Western countries, relatively few included adolescents or older adults, and nearly seven in 10 participants were women.

The authors also warned that standard eating disorder questionnaires may not fit vegetarian and vegan participants well. Some questions can treat deliberate food exclusion as unhealthy restraint even when the reason is ethical or religious, they said, and researchers have started developing screening tools for vegetarian and vegan populations.

The authors said vegetarianism or veganism should not be treated as a warning sign by itself. They said a better assessment looks at fear, distress, escalating restriction and adequate nourishment, rather than the absence of meat or animal products alone.

This story draws on original reporting from Medical Xpress.