In November of 2011, I blogged about a study out of The College of William & Mary that showed that semi-vegetarians scored higher on restrictive eating behavior tests, but that vegetarians did not show signs of disordered eating.

In February, another paper was published finding semi-vegetarians to have higher scores for disordered eating than other diet groups. The paper out of the University of Pennsylvania and Towson University contained two studies.

The first study was a survey of vegans, lacto-ovo vegetarians, semi-vegetarians, and omnivores. The semi-vegetarians were the only group that had especially high disordered scores.

The second study compared only semi-vegetarians to omnivores. Again, they found the semi-vegetarians to have higher disordered eating scores, but the researchers believed some of these findings to be due to the questions not being appropriate for semi-vegetarians; in other words, people who choose to avoid meat are naturally going to score high on questions about avoiding groups of food.

In the discussion, the researchers stated that the vegans had the most healthy scores, healthier even than omnivores, and even wondered if becoming vegan “could actually serve as a protective factor against developing disordered eating.”

As the researchers noted, a flaw in this study could be that, “only those vegetarians or vegans who have healthy attitudes towards food opted to participate.” And, as always with cross-sectional studies, you cannot know for sure if the diet leads to a particular characteristic, or if that characteristic leads to a particular diet.

Reference

Alix Timko C, Hormes JM, Chubski J. Will the real vegetarian please stand up? An investigation of dietary restraint and eating disorder symptoms in vegetarians versus non-vegetarians. Appetite. 2012 Feb 14. | link

In 2009, I blogged about a study in the Journal of the American Dietetic Association that showed that people aged 15-23 who called themselves vegetarian had a higher rate of disordered eating. The study had a strong propensity to detect that vegetarians have disordered eating as their definition of “vegetarian” included people who eat fish and chicken, were only vegetarian for one month, and their definition of “disordered eating” was very broad. I suggested that better designed studies were desirable before any conclusions could be drawn.

Today, a well-designed study was released on-line (ahead of print), by the journal Appetite, and the results were better than I would have expected (Forestell, 2011).

Researchers from The College of William & Mary divided female college students into the following groups:

Vegetarian – 14 of 55 were vegan
Pesco-vegetarian – eat fish but no other meat
Semi-vegetarian – eat chicken and fish but no read meat
Flexitarian – cutting back on red meat
Omnivore – not limiting animal products

Their eating habits and attitudes were surveyed with a battery of questions at baseline and then again one year later.

The results were that vegetarians and pesco-vegetarians did not score higher than omnivores for restrictive eating behavior, whereas the semi-vegetarians and flexitarians did. The authors concluded, “It appears that semi-vegetarians and flexitarians specifically, may be more likely to experiment with restriction of animal products as a form of weight control than vegetarians and pesco-vegetarians.”

Reference

Forestell CA, Spaeth AM, Kane SA. To eat or not to eat red meat. A closer look at the relationship between restrained eating and vegetarianism in college females. Appetite. 2011 Nov 2.   |   Link

Every few years, another study comes out that shows vegetarian teens or young adults to have higher rates of eating disorders than non-vegetarians. The April 2009 issue of the Journal of the American Dietetic Association (JADA) has the most recent one: Adolescent and Young Adult Vegetarianism: Better Dietary Intake and Weight Outcomes but Increased Risk of Disordered Eating Behaviors.

Because eating disorders can result in serious illness, suffering, and death, I do not want to downplay the importance of studying them. However, given that a vegetarian diet is promoted and generally thought of as a good way to lose weight, it should come as no surprise to anyone to find that vegetarians have a higher rate of disordered eating behaviors since many young people try the diet in order to lose weight.

In this study, the researchers’ definition of vegetarian included anyone who had considered themselves vegetarian for over one month, whether they really were vegetarian or not; 25% ate chicken and 46% ate fish. And to be considered someone who engages in disordered eating behavior, all someone had to do was exhibit an unhealthy weight-control behavior or binge eating one time in the previous year.

It’s not surprising that many people who engage in disordered eating behaviors will at some point call themselves vegetarian for at least a month. When you draw a cross section of everyone who is seriously dieting combined with everyone who has cut out at least red meat, you are bound to find some overlap between the two groups.

To actually study if going vegetarian causes people to develop eating disorders, you need to start with a group of people (some vegetarian) who have not previously engaged in disordered eating behaviors and then follow such people through time to see if the vegetarians are more likely to develop eating disorders.

In better news, among the older cohort in the JADA study, current vegetarians were less likely than never vegetarians to be overweight (17% vs 28%) or obese (6% vs 14%), and vegetarian adolescents and young adults reported the highest fruit and vegetable intake. The authors observed that current vegetarian adolescents appear to be at decreased risk for using alcohol, cigarettes, and other drugs.

To be frank, I would guess that even among people without a previous history of eating disorders, vegetarians are more likely to develop orthorexia, an eating disorder characterized by excessive focus on eating healthy foods. We should be aware of this possibility.

Here are two videos on orthorexia:

Part 1
Part 2

Erik Marcus and Ginny Messina have also written good posts on this JADA study.