I am not a scientist, doctor or even a health expert. I have read 50 books or so (see Eating Well) about this general topic. I have a skeptical disposition about any final health solution to the human condition and life on earth. I follow many health bloggers and have been to dozens of health conventions in Toronto where I live with my happy little family of four. I followed a vegetarian diet for some years and became unwell, but in fairness and full disclosure, I was not exercising daily back then as I am now and I was also occasionally smoking. I put on 50 pounds which I have since shed. I use the concept "Skinny" as a metaphor within one's genetic inheritance; i.e., if your parents were rotound, then be skinny-rotound, or as healthy as you can be within the margins of your genetic makeup; I don't use the concept in its literal sense and I hope you won't either. Some folks have a genetic lean to being overweight as low as 25 percent and as high as 80; however, having said that, I know  many people who were skinny teenagers who are totting around an extra 100 pounds in their fifties and a few even much more than that.
 I have been following a paleo regime for more than ten years currently (2022). I have no inflammation, scamper at my teenage weight, haven’t missed any more than three or four days without exercising in that timeframe and have been without even an aspirin or any drug since then. As I have become incrementally stricter in compliance—eating grass fed, grass finished meats, wild fish and shell fish, range eggs (which sometimes aren’t even actually what they claim)—I started to reduce my protein intake to occasional omega eggs and wild fish. In a typical well stocked grocery store there are often no “healthy” meat proteins to buy, or if by chance there is, the price is a serious deterrent. Buying traditional farm raised meat directly from a local farmer is a good protein option but would it perhaps be for many too much bother in a busy life as it was for me?
 So I found myself practically vegetarian without even meaning to, certainly not out of principle or from a faith in the scientific data. When I watched Christina Warinner debunking Paleo on Tedx, I enjoyed it and realized that though technically right in what she presented, she was arguing against a straw dog; much as I argue against Platonism in many of my articles and that unlike me she really hadn’t taken the time to read the authors of the movement in-depth. She got the basic science right about whole foods and that was good enough for me. Rather it was when I saw the dishonest, Michael Moore-ish Netflix’s What  the Health that I decided to review the sources that the documentary used. As for the movie itself, its tone, characterizations, it’s misuses of the data, the full fury of its conspiracy theory of the market economy and democratic government, the almost jam-packed promotion of sugar and refined carbohydrates, it was all pure piffle and made me retaliatory. I seriously wondered if they accepted funds from the sugar industry to make it or if there was some backroom deal between The Processed Food Industry and Netflix. (The Game Changers is another example of this, also all personal stories instead of science, and  an unrepresentative view of a whole food, Paleo or Keto diet, and again, athletes ordering plant-based food from fast food places; they just don't get it.
After I had read The Pleasure Trap, I was impressed with the tenor of the discussion in the book and the half-attempted scientific objectivity, although they truly misrepresented the paleo position and other diets of the whole food community. Also, the authors show little self-criticism—they’re on a mission—I get that, but that doesn’t mean they can overthrow their objective disposition as scientists. They of all people always have to have a good measure of doubt. That’s in truth their number one job. The authors sell it all like creed; however, as you will read below, scientific scepticism is the most important tool we have to get us from social myth of what we can and cannot consume—the information you get from community, family, online, work associates, magazines and etcetera—and the naked scientific facts. What is emerging from all the data is a monumental case against eating any processed foods and for getting an immense amount of exercise.
One of the first health books I had read some years ago when I began to reject the modern Western diet was the Omnivore’s Dilemma—‘If it came from a plant, eat it; if it was made in a plant, don't’—still one of the finest written, most brilliant books on these complicated matters. Another was Why We Get Fat still worth every reader’s attention. The vegan’s claim that we are herbivores, like our cousins the chimpanzees—this at least in an evolutionary sense—is exceedingly thin. In fact even chimps and baboons will eat meat if they can get it. With the long ago development of big brains Homo Erectus was eating meat and lighting fires some many millenniums before the arrival of us one hundred thousadn years or so ago. How much meat? It is clear that at present the science is not yet certain.
Fat is not necessarily fat and calories-in and calories-out happens not to be entirely true. What exactly makes visceral fat in humans (i.e. we fatten up cattle, hogs and foul with corn and soy feed) and how we lose it (i.e., it takes less energy to put on than to take off) are much debated between vegan and paleo and every diet in-between. Everyone off the payroll agrees that the industrial product created in the torture chambers of the modern slaughter plants is evil. This meat we did not evolve to eat. The fat content is deadly! But of course fruit vegetable nuts legumes most which have been modified by human genetic tinkering for many generations, also don’t much resemble plants we evolved eating. I had a discussion with a customer one day recently and she refused to buy G.M.O., apples or other such products but she had chocolate bars potato chips and frozen pizza in her cart; whatever her logic it doesn't reflect any serious rationality
Paleo and vegan camps both agree that the West’s lifestyle is a failure and that like cigarette smoking, we are exporting it abroad. However, this is not their only agreement. In fact in 80 percent—this figure is arbitrary—of what we should be eating and in 90 percent of what we shouldn’t be eating, there is complete accord. As well, a super fit Mediterranean diet (and low carbohydrate, low fat and many others) are all vast improvements on our typical nutritionally deprived fast-food Western diet and they—independent nutritionists—all concur: There should be no consumption of processed foods, (including industrialized meats) and don’t eat in restaurants. Instead, eat plants, especially green ones like spinach, kale, broccoli, cabbage, and etcetera. So, let’s start there.
I am no longer a vegetarian, but I have tremendous respect for them and vegan-s, if they actually combine their food choices with the proven stress/exercise/sleep/gut rules driven home by so many health experts/scientists/ doctors/ and nutritionists in numerous books from all around the world, many listed below or in the body of this article. To people of any persuasion in these matters who are ideological, I have nothing but compassion—wanting a thing to be true without proof, living with doubt and sustaining a skeptical position against miraculous claims is hard. It is the same as religious belief whether in a supernatural dimension, a utopian situation or an unrealistic state of health. Humans are incredibly subjective. If one wants to see science (i.e., exact causal relationships like smoking and lung cancer, where many have not yet been proven) they may well end up disillusioned. The thing I comprehended after reading Cordain, Sission, Whals, Wolfe, Gundry and Kruse is that they are far more cautious of their claims, self-effacing in their wit and more self-critical than the vegan authors I discuss below.
We see in the vegan community a close connection of authors, studies and citations. The Pleasure Trap is no different—keep in mind, the same phenomena occurs with the paleo folks—and a lot of them from both groups cite many of the same studies, which is pretty amusing. In this work, I am not sure the authors’ definition of human happiness hits the mark as I understand it. We do indeed know something about happiness, see: The Conquest of Happiness, The Power of Habit and Authentic Happiness. Whatever this illusive human pursuit is, I agree that our biological health is an important component of it. In this regard their attack on the typical western diet is immaculate. The paleo friendly Warrior Diet deals for instance, as do many paleo works, with fasting, resistance exercise, aerobics and so forth. Here too there is universal agreement. Detoxing the modern diet to restore gut flora (also a major paleo concern), plus discussions around leaky gut, insulin resistance, the need for uninterrupted sleep—the only failures in this work are lack of strict sugar restrictions, caution about night-shades, lectins, gluten and legumes (overcome with proper preparation), and avoiding too much whole grain, especially processed cereal—flaked grains will not help your overweight problem.
How Not to Die is a 1500 page treatise which makes huge and perhaps unrealistic claims that no responsible paleo writer would ever make. A person’s reputation would be in ruination if one oversold what foods can and cannot do. The author cures every modern manmade ailment known to us with plants. Nonetheless, while they caution about the alleged sodium co-relationship with blood pressure, they lay the blame for the diabetes epidemic not on processed sugars and foods but mostly on animal fat. While it may well be a contributing factor, it is hard not to believe that the main culprit here is pure, white and deadly. Metabolic syndrome is not even mentioned in the work, only foot-noted, but at least they get the amount of exercise right. Ninety minutes of walking a day (i.e. vigorous daily work out) is so essential for long-term health; in a lot of vegan literature  exercise is relegated  to a few remarks or a short chapter, which is a blindside to the scientific literature which the paleo crowd don’t ever skip—not one single one that I have ever read.
As for My Beef with Meat, there is a complete misrepresentation of not only paleo but every other diet except a vegan one, and maybe not even that one. As you might guess by the title—meant to be ironical but merely falling on the ear as cliché—is a tirade against animal protein in any form. Here’s a funny quote from the book: “I looked at the menu and lo and behold, I found a vegetarian sandwich. And not just any sandwich. To a toasted bun without butter I was able to add as many items as I wanted from a list of great-looking vegetables. I went to town! Grilled onions, grilled mushrooms, jalapeño peppers, green bell peppers, lettuce, pickles, tomatoes, fresh onions, all topped off with barbecue sauce. It was terrific. And it cost a jaw-dropping $2.89!” Can you imagine? He’s a grazer eating processed starch, salt and sugar products like an ignoramus and writing a health and wellness book.
While passion for eating plants is an admirable trait, his single focus against meat destroys any nuance. His philosophy is lacking any sophistication, so much so, that even if some of his arguments hold warrant, they’re rejected out of the principle: “Methinks dost protest too much.” He’s like a former smoker making us ‘too’ aware of the dangers of smoking but exaggerating the data and finding conspiracy everywhere. Although if you’ve read The Cigarette Century there was indeed quite a plot among the tobacco lobby, but the point is, if you’re going to say this and that about paleo or other lifestyle choices, then at least put them in their best light. Their science is as solid as vegan's. On a super fit paleo diet there is nothing for you to eat in a supermarket except organic produce if you can find some. Paleo authors are respectful of vegan-s, many like Gundry, and Wahls offer alternative recipes for them. Science dictates these choices, and you are no more allowed an industrialized prime rib than a bottle of coke and a mars bar. My advice to the author is, if you’re not willing to entertain, for instance that the nightshade family of plants might have a downside or that bean-eaters have to take precautions, you are cherry-picking your way into ill health as some paleo practitioners would say Ancel Keyes did to all of humanity in his Seven Countries study. Moreover, the ridiculous recipes contained in this book are a formula to get fat. Eating vegan, like paleo, has serious health consequences if you are not careful.
Power Food for the Brain is a straight forward vegan work, but he can hardly even deal fairly with the essential B12 complex, instead suggesting supplements and urine tests to make sure you’re getting enough. It’s strange to the ear isn’t it? I mean just have some fried liver with onions, spinach and sautéed with apple cider vinegar once in a while. Well you’re vegan, I get it. One of the authors joked about eating dirt to get this essential vitamin (it comes from earth and we get it naturally from animal protein). I guess that’s funny. Wild fish and range eggs get you an iodine hit you can’t get from plants. Suggesting the use of iodinized salt also sounds wrong, doesn’t it? They have demons that they don’t want aired. Evolution dictates what we need to live healthily. Emulating it to be at maximum wellbeing is a goal of paleo and should be for vegans. We read their literature and learn a lot, but it seems the goodwill is not returned.
All of life is a trade off. Eat enough plants and you might have to worry about artificial bug killers used on them, like eating tuna and being anxious about mercury. Surprisingly he doesn’t seem to understand neuroplasticity and suggests online games to keep your brain sharp. The science for this conclusion is non-existent. However he at least gives lots of space to exercise and how it impacts brain health. As for sugar, I guess he’s never heard that they’re calling Alzheimer’s, diabetes of the brain. And about salt, there is very little information here--although in fairness to sodium intake and your overall health--if there is absolutely no processed food in your diet some added salt to your raw or cooked vegetables might be called on for depending on the amount of activity, the weather, your age, weight and your toleration to sodium, for instance I make my own sauerkraut and put that on my salads, and this is a steady daily stream from dirty salt. And like many vegan-s, he mixes all fats into one vast vat and presto, they are all equally evil. Utter nonsense as any of the cholesterol books listed below will explain.
In Prevent and Reverse Heart Disease there are plenty of anecdotal stories of success with patients on their death bed with heart disease, many literally sent home by the medical community to die. In these critical cases, perhaps an ultra low fat vegan diet is godsend. Like Wahls Protocol, he claims amazing success similar to the astounding results in MS and other distressed autoimmune patients in burning ketosis and feeding mitochondria under high fat procedure in Whals’ regime. She has a workable (as of yet unproven) theory. However, here again we see between the two factions a subjectivity bias. Wahls is actively raising millions of dollars for larger studies; Esselstyn rather than do this or plead the case for more research money, takes the cynical view that the market economy is at fault, and blames big money holders for resistance to his ideas—that they are actively working against him. If only it were that simple. Many in the vegan community are beholding to The China Study, a flawed, even debunked  work, and their collective antithesis to objective independent criticism of their cherished study is understandable when looked at with the ideological component. On the paleo blogs, you never see the ignorant, almost childish rants and name-calling that you do when (I assume youthful) vegan's rush into the fray and personally attack someone who has criticized their esteemed scientific data; it is reminiscent of the environment movement.
If you’ve come across McDougall’s  The Starch Solution Diet you might be surprised that he uses the word starch like paleos and vegans sometimes use their labels:  as if some magical potions for good health.  Hunter gatherers in Pupa New Guinea practically lived on sweet potatoes until 50 years ago and they were trim hardy and healthy; no process foods, periods of hunger and plenty of exercising do that. We've been eating starches for about 20 thousand years now. McDougall calls his intellectual competitors fat and liars like some pouting ideological twelve year old. For shame.
Vegan apologists go to some lengths in supplying statistics of food-poisoning and resulting deaths from salmonella, listeria and other bacterial infections introduced into the food chain through meat products. They ignore massive recalls of fruits and vegetables (with also many accompanying fatalities), from plants contaminated with e coli, botulism and other deadly microorganisms. This is to say nothing of the fact that many plants themselves are outright toxic, poisonous, and some causing death; for instance, the nightshade Belladonna is one such plant—tomatoes, peppers and potatoes are in this family of plants—a few berries ingested can kill a child.
Years ago after I had read Eating Meat and became a vegetarian, but I ate veggie junk food, smoked and changed little else in my lifestyle. It was easy for a time but in fours years I became unhealthy. With a great deal of help from a dear friend, I began my research on better lifestyles. In regards to paleo, I started with The Primal Blueprint which sells keeping fit as a complete commitment to lifestyle; there’s no missing the message about exercise and its importance to paleo.  Neither vegan nor paleo (Pegan perhaps) seems to be as important to longevity as a balanced diet reliant in plant based foods with pressure-cooked legumes if you wish but they are not indispensable. Eat a small amount of protein from only the finest animal products. Get grains out of the mix, especially cereal. Being part of a large extended family, group of friends, tribe, and small community is essential to your well-being—even contact on a daily basis. Sleep well, manage stress by finding flow and get lots and lots of activity. Indispensable nutritional knowledge make it obvious that a high-quality lifestyle requires exercise and a diet of unrefined and unprocessed whole foods of the most optimum value available. Also, remember, everything is problematic. Strictly plants? Think pesticides. Firmly legumes? Consider lectins. Grass-fed range meats? Imagine butchering and eating living-feeling creatures. So don’t go off half-cocked and righteous, it is just plainly wrong. You can be adamant about two things: not eating what came out of an industrialized meat plant and eating organic locally grown plants, but other than those, tread softly and look to your own. 
There seems to be a consensus of sceptics out there in the blog-o-sphere that up to 90% of all diets don’t work long-term. That over the years it is almost impossible to lose-and-keep off the weight you’ve lost. But there seems to be some hope in the fact that better choices in lifestyle, what foods one eats and daily exercise without a conscious effort at actual weight loss might improve success in the long-term, i.e., if you make it about your health and happiness and not about your appearance, for help see here, here and here. Diets like the Mayo Clinic One, (a form of Mediterranean Diet), the Whole Food, Low-CarbohydrateKeto, Vegan and Paleo diets all have helped millions of people to lose and keep weight off as a permanent lifestyle change; these diets remember-no matter what you hear-are far more similar than they are different. What they share is that 90 percent of your diet with their methods becomes fresh fruits and vegetables with an emphasis on physical activity. Here listed below are some of the books I have read on the subject.
 
The Primal Blueprint, M Sisson
Wheat Belly, W Davis
Grain Brain, D Perimutter
The Paleo Diet, L Cordain
The Brain that Changes Itself, N Doidge
Seven Countries, A Keyes
Warrior Diet, O Hofmekler
Why We Get Fat, G Taubes
The Great American Heart Hoax, M Ozner
Omnivore's Dilemma, M Pollan
The Vitamin D Solution, M Holick
Fast Food Nation, E Schlosser
EPI-Paleo RX, J Kruse
Fat Chance, R Lustig;
Pure, White and Deadly, J Yudkin;
Eating Well For Optimum Health;A Weil;
How to Eat, N Lawson & A Boehm;
Eating Animals, J S Foer;
The Vegetarian Myth, Lierre Keith;
Salt Sugar Fat, M Moss;
Becoming Vegetarian, V Melina and B Davis;
Nutrition and Your Mind, G Watson;
Wahl's Protocol, T Wahls;
The Paleo Solution, R Wolff
Death By Food Pyramid, D Minger
New Evolution Diet, A De Vany
Use Your Brain to Change Your Age, D G Amen
The Paleo Comfort Foods Bible, A Conrad
The Art and Science of Low Carbohydrate Living, S D Phinney, J S Volek
Practical Paleo, D Sanflippo
Big Fat Surprise, N Teicholz
Brain Maker, D Perimutter
Live Long, Die Short, D B Agus
The Great Cholesterol Con, M Kenrick
The Cholesterol Conspiracy, R L Smith
The Cholesterol Myths, U Ravnskov
The Great Cholesterol Myth, J Bowden, S Sinatra
Cholesterol Clarity, J Moore, E C Westman
The Pleasure Trap, Lisle and Goldhamer
How Not to Die, G Stone
My Beef with Meat, R Esselstyn
Power Food for the Brian, N D Bernard
Prevent and Reverse Heart Disease, C B Esselstyn
The Plant Paradox, S Grundry
The Starch Solution, J McDougall
The China Study, C Campbell
The Salt Fix, J DiNicolantonio
The Blood Sugar Solution, M Hyman
Eat, Drink, and be Healthy, Willet and Skerrett
Healing with Whole Foods, P Pitchford
Cook Yourself Thin, C Kumai