Vegetarian Recidivism Survey

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.


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10 Responses to “Vegetarian Recidivism Survey”

  1. Don Says:

    “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.”

    This laundry list is useless. Depression/anxiety, digestive problems, food allergies, eating disorders, and thyroid problems are not unique to nor specifically caused by abstaining from meat consumption. How many meat-eaters have these symptoms or disorders? Further, who did the diagnosis? The individuals themselves? Or were these medically confirmed AND consequent to eating a vegan or vegetarian diet for a few months, not pre-existent or imagined or circumstantial (e.g. someone adopts a vegan diet for a few months, during which she loses a significant other, and becomes depressed…the depression came during the diet but it is not due to the diet).

    And with this list: low cholesterol, protein deficiency, B12 deficiency, calcium deficiency, iron deficiency, iodine deficiency, vitamin A deficiency, vitamin D deficiency, zinc deficiency. Low cholesterol is not a disorder if it is in the normal range. Are we talking about dietary deficiencies, or actual physiological deficiencies with defined syndromes? Who made the diagnosis, the individual or a medical or nutrition professional? Or an unqualified individual (friend, insufficiently trained individual, low carb diet doctor, Sally Fallon, etc.)? What are the diagnostic criteria for protein deficiency? How about calcium deficiency? Did these people develop osteoporosis in a few months without milk and meat (LOL)? Are any of these “deficiencies” unique to individuals who abstain from milk, meat, and eggs?

    Without proper medical evaluations, asking former vegetarians or vegans what disorders or deficiencies they developed is obviously a very poor way to evaluate whether or not abstaining from eating animal products caused any medical or nutritional issue among them. I am speaking as an ex- ex-vegan. I know the capacity for self-justification and deception and rationalization when one is surrounded by meat-eaters who are only too ready to blame any problem that occurs in vegans as a result of avoiding eating animals, when in fact those very problems occur a plenty among people eating animals. I really can’t take any of this SURVEY data seriously.

  2. Don Says:

    I will add that I practice acupuncture and Chinese medicine. I have my clients fill out a health history and current health status form at their first visit. The vast majority of my patients are non-vegetarians. Yet at least 90% of them complain of fatigue on their first visit. Fatigue is not uniquely caused by avoiding eating animals, nor is it reliably prevented or cured by eating animals. Yes, there are some instances where vegans fail to get adequate B12, iron, protein, or calories, resulting in fatigue. But fatigue also is a common result of being stressed, and when one is stressed about one’s food choices, and in conflict with friends, family, or other social groups over it, fatigue may result without there being any dietary cause for it. Fatigue also can occur from overworking and not sleeping enough. Hypervigilance for dietary ’causes’ prevents many people eating plant-based diets from rationally evaluating other potential causes for their fatigue, particularly stress.

  3. Consistency Says:

    Have you seen the ingredients in Red Bull?

  4. Sanek Says:

    Hi, Jack.

    (off-topic) How Much Protein Can You Absorb and Use from One Meal?

  5. Jack Norris RD Says:


    Unless you have a malabsorption syndrome, you will absorb just about all the protein you eat. As for how much you can use, you will only use the protein you need to build muscles and other tissue, which is what the RDA is created to estimate (with some extra buffer). The rest of the protein you absorb will be either burned as fuel or turned into fat. You can find protein RDA here in Table 1:

  6. Sanek Says:

    Jack Norris,

    I can eat a RDA protein two shots? On the morning of 55 gram and 55 gram evening. My digestion can provide all essential amino acids?

    p.s. Sorry very bad english.

  7. Jack Norris RD Says:


    My protein recommendations are here:

    More info here:

    You might try using Google Translate if you can’t understand them.

  8. dave r Says:

    As more quality vegan convenience foods continually become available, I imagine that recidivism will drop even more. I’m especially thinking of future vegan fast food restaurants, etc. One thing I wasn’t quite prepared for when we went vegan was how much cooking on my own I would have to do. Being vegan is still quite “inconvenient” as far as availability of already-prepared food, but it won’t always be. I read about folks that went vegan back in the 80s and 90s and realize how easy we have it right now as far as ready-made choices go. Still, the limited at-hand options can easily lead to nutritionally-poor food choices.

    I am convinced that one reason our family has thrived on a vegan diet is because we follow all of your (Norris) advice. We also follow Messina. Basically this just means making sure that we are getting our RDAs. (or is it DRIs now?!) We are aware of potential pitfalls and supplement accordingly (iron for my wife, calcium for all three of us, b12, vitamin D during winter, iodized salt, etc.) Mostly this is “invisible,” via fortified soymilk, juice, etc. I know we would be deficient like the people discussed above if we weren’t taking these steps. In fact, supplemental iron for my wife and additional vit D for both of us was prompted by routine bloodwork that showed they were low. But iron deficiency and low vitamin D is certainly not a problem exclusive to vegans, as we all know. Very common.

    It’s discouraging that in 2014, there is STILL so much bad nutrition information out there – and so much of it pushed by vegans themselves! For example, recently, there was a multi-page article in Vegan Health and Fitness arguing why it was unnecessary to supplement B12. Yikes! I couldn’t believe it. Just what we need, more prescriptions for people to ruin their health.

    I was not willing to go vegan if it meant compromising my own health. My health had to stay the same, at a minimum. And it has, going on seven years, thanks to your expert guidance here and on Actually, I would say that I’m healthier overall and not just the same, but I would never have gone vegan for the health reason alone, and in my experience it’s mostly ineffective trying to effect change in people on that level, so I don’t typically try to sell vegan health benefits, despite having experienced some of them myself. (Notably, blood pressure drop and cholesterol drop).

    Thanks for leading the way and for keeping us so well-informed.

  9. Catherine Says:

    Hello Jack,

    I have been an ethical veg*n for over 25 years now. In those years I have studied natural therapies, raised a vegetarian son, and also been part of animal welfare movements. I have therefore come into contact with many veg*ns (vegetarians and vegans) whose reasons for being so were varied. I thought you might be interested in what I have found regarding recidivism. I will not attempt to list any conclusions here nor pass any judgement, but simply tell you what I have found through my own questions and observations over the years.

    Without a doubt those I have known who are veg*n for the animals are almost always more determined to stick with it. If they have encountered health problems they have worked out ways to deal with it. The main complaint I hear of is Iron deficiency which has often shown itself quite quickly and then responded to fine tuning the diet and supplementation if need be. I have known more vegetarians who have problems with iron than vegans. I myself have never had to supplement with iron although my son has needed to during growth spurts. I do need a top up with zinc every now and then ( I start to get mouth ulcers which respond to the zinc). We both take B12.

    I have known some who went on very restrictive vegan diets for health reasons, most but not all went back to eating meat. Many of these tried raw food diets or the very low fat diets and would not take supplements wanting to eat only pure foods. Some of these are now on Paleo or the high fat “cholesterol is good” for you diets.

    I know some who strive to be vegetarian for spiritual and or environmental reasons but seem to feel like they “need” to eat some but not a lot of meat to be well. I also know some long time elderly ex-vegetarians in this category who feel they no longer have the digestion to get what they need from plant foods. Most of these are men.

    I also know some short and long term now ex-veg*ns who admitted they were tired of the social isolation and difficulty when eating out and some who were simply tired of having to provide multiple meals at home to cater for different food choices. I would fall into this category with regards to wavering between vegan and vegetarian.

    Thank-you for reading and I hope you found this of some interest.

  10. Jack Norris RD Says:

    Thanks, Catherine, I did find that interesting.

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