The underlying motivation for my nutrition work is to prevent vegetarian/vegan recidivism. I have focused on nutrition and put myself out there as someone who will help people who are having health issues with becoming vegetarian/vegan. Because of this, I regularly hear from people who are struggling and it can sometimes seem like a lot of people, but I know my view is likely skewed and I have always wanted to know just how many people quit due to health difficulties.
On December 2, the Humane Research Council (HRC) released a report, How Many Former Vegetarians Are There? which sheds some light on this question. I helped out a bit in designing some of the nutrition-related questions and have been anxiously anticipating the results. I would like to thank HRC and all the people who funded this important research.
A quick overview of the report is that it was a cross-sectional survey of 11,000 people in the USA aged 17 and older. They found that 2% are currently vegetarian/vegan, 10% are ex-vegetarian/vegan, and 84% of people who go vegetarian/vegan quit.
The researchers used a high bar for determining who was vegetarian/vegan and ex-vegetarian/vegan – the participants had to answer a food list questionnaire indicating that they were vegetarian/vegan and then also say that they considered themselves “vegetarian” or “vegan”. I have not seen such a high bar used in any previous research.
Their report covers many of the difficulties former vegetarians/vegans had on the diet, but I’m only going to focus on the health aspects in this post. I have more to say about the rest in my post Humane Research Council Survey on Vegetarian Recidivism on Vegan Outreach’s blog.
The HRC blog post linked above does not include much information about health issues, but their complete report (which you can access by signing up for a free account on their site) has more. Below are excerpts followed by my comments.
“Former vegetarians/vegans were asked if they began to experience any of the following when they were eating a vegetarian/vegan diet: depression/anxiety, digestive problems, food allergies, low cholesterol, an eating disorder, thyroid problems, protein deficiency, B12 deficiency, calcium deficiency, iron deficiency, iodine deficiency, vitamin A deficiency, vitamin D deficiency, zinc deficiency. The findings show that 71% of former vegetarians/vegans experienced none of the above. It is quite noteworthy that such a small proportion of individuals experienced ill health.”
HRC sounds pleased that only 29% experienced ill health – but that’s almost one-third of people who tried the diet. I was actually hoping to find out that, say, only 1% of former vegetarians experienced poor health because it would allow me to retire from my nutrition work that, while being a labor of love, is indeed a labor, and takes away from my other efforts. At almost 1 out of 3 people, I’m not so sure it’s time to cross the finish line and declare victory.
“All of the conditions [listed above] were experienced by some participants, though only rarely. In each case, less than 10% of lapsed vegetarians/vegans experienced one of these issues, except iron deficiency (experienced by 11%).”
Fatigue is the most common complaint I hear. I have not found any one explanation for most cases of fatigue though vitamin D deficiency and iron deficiency in female endurance runners are common.
The fact that B12 deficiency was not a big complaint is not surprising given that overt vitamin B12 deficiency symptoms normally take years to develop whereas most of the former vegetarians/vegans were only on the diet for a few months, and any lacto-ovo-vegetarians would be getting B12 from dairy and eggs.
“Respondents who indicated they began to experience at least one of the conditions were asked if it improved after they started eating meat. 82% of these respondents indicated that some or all of the conditions improved when they reintroduced meat. The most typical timeframes for improvement were: within 2–6 days (20%), within 1–3 weeks (33%), and within 1–3 months (22%).”
Interesting. For some people who come to me with severe problems that we cannot seem to solve, I have often wondered if I should suggest they try going back to eating animal products, reset their health (if it does in fact reset), and then try becoming vegetarian/vegan again more slowly.
HRC emphasized the rates at which vegetarians/vegans had gotten their vitamin B12 levels checked. I would find this somewhat irrelevant other than as a marker for knowing that vitamin B12 is important for vegans. I generally discourage vegans from getting their B12 levels checked as a way to prevent B12 deficiency in most cases because of the unreliability for people who regularly eat seaweed (including sushi) and the fact that no matter what your B12 levels turn out to be, all vegans should be getting a regular, reliable source of B12 (see Should I Get My B12 Status Tested?).
In their section on Taste, they found that about one-third of former vegetarians/vegans craved meat compared to about 8% of current. It’s a mistake to consider “cravings” and “taste” to be equivalent. You can’t simply add the taste of meat to a low-fat, low-protein vegetable and expect that to take away someone’s meat cravings. Meat cravings are about the nutrients, most notably fat and protein. Craving the “taste” of meat is a Pavlovian response for craving those nutrients. (Note: I don’t know if this has been scientifically tested in a rigorous way.)
There were two positive findings from the HRC report:
More than one-third of former vegetarians/vegans said they are interested in resuming the diet, and vegans were less likely to abandon the diet (at rate of 70% compared to 86% for vegetarians).
The rest of my comments on this survey are regarding what it means for advocacy. If interested, please see Humane Research Council Survey on Vegetarian Recidivism.