The term “pegan” was coined by Dr. Mark Hyman, a preventive medicine specialist who has helped his patients achieved good health with diet for many years. His recommended diet has elements common to both paleo and a healthy version of a vegan diet, so he calls it The Pegan Diet, and recently wrote a book with that title. This is a very good book which I review below. First I’ll give my take on the compromise between the Whole-Foods Plant-based (wfpb) diet, of which a healthy version of a vegan diet is a subset, and the paleo diet. I think this compromise removes extreme aspects of both diets, and ends up fitting in well with mainstream guidelines.
I discussed previously, wfpb emphasizes strict avoidance of overly processed foods (or as I summarize them, “junk”). It allows pretty much unlimited amounts of unprocessed fruits, vegetables, and legumes. Plenty of grains are also allowed, as long as they are minimally processed. Wfpb also recommends reduced consumption of animal products, including dairy, meat, and fish. Taking this to the extreme eliminates these products entirely, resulting in a whole-food vegan diet. But in my opinion, this is not necessary as I’ve explained previously (for example looking at the healthy and long-lived Blue Zones populations, most of them consume some animal products, up to about 10% of their calories).
Paleo has a lot of similarities to wfpb. It also emphasizes strict avoidance of junk, and allows pretty much unlimited amounts of unprocessed fruits and vegetables. It also recommends limiting dairy consumption. Where it differs is that meat and fish consumption are not limited, but consumption of grains and legumes are. This is all based on an estimate of what hunter-gatherer (or “pre-agricultural” populations ate. Originally paleo diets recommended eliminating grains and legumes, because it was thought they were not eaten by hunter-gatherers. Now there is evidence that at least some grains and legumes were eaten before the advent of agriculture, but probably considerably less than what is eaten in typical modern diets. Just as an extreme version of wfpb is vegan, an extreme version of paleo is no grains, no legumes.
A further complication is that there are both lower fat and higher fat versions of paleo. The former is based on the assumption that wild meats consumed by hunter gatherers were much leaner than modern meat from domesticated animals. The latter is based on the counter argument that typically more parts of the animal are consumed by hunter-gatherers than just the muscle meat, and other parts such as organs are higher in fat. Another important factor is hinted at by this argument. If it is true that our ancestors evolved eating a lot of different parts of the animal, but in modern diets we now eat almost predominantly muscle meat, might that have health effects? One paleo author has argued in a post on “eating the odd bits” that this might be why studies show excess animal protein has some health issues, because we are not getting a balanced profile of amino acids. There is concern about toxic materials getting concentrated in parts like liver, which would be a reason to insist on only organically raised grass-fed meat if you try this. Dr. Hyman emphasizes that in his book.
Mainstream nutritionists usually are somewhat dubious about the extreme versions of both these diets because they eliminate “entire food groups”, but in my opinion in the version where wfpb limits but does not eliminate, meat, it is compatible with mainstream guidelines. Also, in my opinion, the lower fat version of paleo, that limits, but does not eliminate, grains and legumes, is compatible with mainstream guidelines. Mainstream nutritionists may object that it is still a higher meat diet, but I’ve argued previously that is does not have to be. For example, the last remaining hunter-gatherer population of earth, the Hadza people of Tanzania, eat a diet of about 70% plant foods, and 30% lean meat. I should point out that the Hadza are not counted as a “Blue Zone” population, because they do not have higher longevity than typical modern populations. But they have much lower incidence of modern chronic diseases like heart disease and cancer. As for longevity, they do not have access to modern medicine, so have a higher infant mortality rate. If they reach adulthood they are likely to live to at least 70. And even then they tend to die of things like infectious disease rather than modern chronic diseases. It it quite possible that they would reach “Blue Zone” rates of longevity if they could get modern medicine.
The higher fat version of paleo does not meet with mainstream guidelines because it tends to allow more saturated fat than is normally recommended. As I’ve discussed, advocates of the higher fat version do not agree with the reasoning about saturated fat. For example, ldl cholesterol may not be low on this diet, but hdl cholesterol tends to be high, and triglycerides low, and this makes ldl less likely to oxidize, which is an important factor for preventing heart disease.
I have been following wfpb for a little over four years now. In my experience, it is much more important to be strict about the “whole-foods” part than the “plant-based” part. If I stray from whole foods I’m likely to have cravings for junk foods return, like cakes, cookies, etc. But if I eat some meat for lunch it is unlikely to trigger a meat binge. Some wfpb authors might object that it is unhealthy to eat more than about 10% meat, based on the Blue Zones argument. Another argument is that excess meat in the diet can start changing our gut microbiome in an unhealthy direction. But even Dr. Bulsiewicz, who is a wfpb advocate based on fiber and gut health arguments, admits that the Hadza are exemplars of a high fiber diet and probably have good gut health, and we know they eat considerably more than 10% meat. The Hadza do eat an astonishing variety of plant foods (about 600!), and get about 100 grams of fiber a day, far exceeding modern dietary recommendations. What if it’s the high fiber content and high diversity of plant foods that matters most? It is true that excess consumption of animal protein correlates with increased risk of all-cause mortality, but that is in the context of a modern diet, which has a lot of junk (like refined carbs) and not enough fruits and veggies.
Dr. Hyman’s Pegan Diet
If you start with the wpfb diet, but reduce consumption of grains, and allow a bit more meat, you pretty much end up with Dr. Hyman’s pegan diet. He starts out recommending A lot of fruits and veggies, up to 75 percent of your plate. Dr. Hyman calls this “whole-foods plant-rich”. I like that term as opposed to wfpb, because it save you from always explaining why “plant-based” doesn’t necessary mean no meat. The remaining 1/4th is for protein sources including meat and legumes, as well as some grains. He has had lots of patients with grain sensitivities, so especially wants us to be on the lookout for digestive issues with grains (and some legumes). It may be healthier for those with issues to substitute gluten-free grains, or even “pseudo-grains” like buckwheat. But he feels grains are not as nutritionally dense as other plant foods like fruits and veggies, so even for those without sensitivities, he recommends not eating too many calories from grains.
Dr. Hyman emphasizes the importance of adequate and good quality protein. As I’ve discussed previously, this is even more important for aging adults, to prevent loss of muscle mass (sarcopenia). He admits that it is possible to get adequate protein on a vegan diet, but you have to know what you’re doing, with proper foods combinations to get a good blend of amino acids. But it is much easier to get enough good protein if you allow some meat in the diet. There are other possible deficiencies like vitamin B12 that he discusses, that may be avoided via supplementation, but are not an issue if some meat is in your diet.
Dr. Hyman has 21 principles to his pegan diet. This sounds complicated, but the diet can easily be summarized as something like “eat lots of fruits and veggies, limited grains, and a decent amount of meat and legumes”. The 21 principles add additional nuances. There is a chapter for each principle, such as “eat the right beans, whole grains, nuts, and seeds”, “eat your meat as medicine”, “be picky about poultry, eggs, and fish”, and “treat sugar like a recreational drug”. The book is a very good source of info on high quality foods sources, like grass-fed beef, and sources of fish that are least likely to be polluted.
I also thoroughly enjoyed the chapter “eat like a regeneratarian”. A regeneratarian eats foods sourced from regenerative agriculture. This is a very good condensed version of the environmental arguments against conventional agriculture, and in favor of regenerative agriculture, of both plants and animals, that agrees with arguments in the book Sacred Cow. I used to consider myself a “reduceitarian”, or someone who eats a reduced amount of animal products for environmental reasons. I now instead strive to be a regeneratarian (it is possible to be both, but now I believe regeneratarian to be more important than reduceitarian).
I highly recommend this book, especially for those who are confused by conflicting arguments coming out of the wpfb and paleo “camps”. Following the principles in this book will improve your health considerably, especially in contrast to typical modern diets.