As I promised a while back, I’m finally going to go over what I’ve learned about various diet alternatives. And I reiterate I mean “diet” more in the sense of long-term way of eating. There is some controversy about what I am about to cover, even though I tried to present balanced evidence and look for what’s in common among various approaches. Far and away the biggest takeaway on diet is just following the “healthy eating rules”, rather than any specific detail that might be controversial. I’m trying to clear up misconceptions and confusions here, not muddy the waters further. And I think it’s important to have the attitude that there are no forbidden foods (except something you’re allergic to), some are “staples of your diet” to be eaten liberally, others are “special treats” to be eaten less often.
I’ll give some references to back up my comments, but to keep this post as more of an overview, I’ll defer more detailed evidence to future posts. I’m a bit nervous about posting this one because it strays from the mainstream and gets into more controversial territory, but here goes.
I think the main takeaway is that there’s a lot more overlap among these ways of eating than commonly thought. Paleo and vegan are often presented as complete opposites, for example. But a healthy version of vegan can be shown to be a subset of whole foods plant based (wfpb). And paleo is more flexible than often depicted, and if it is tuned towards lower meat consumption can actually be a subset of wfpb, if that is also interpreted more flexibly.
Wfpb (Whole Foods Plant Based)
A whole foods plant based diet gets a reduced percentage of its calories from animal products, the rest from a variety of healthy plant foods. There are data on healthy and long-lived populations around the world that eat this way . In addition to the population data, there are also intervention studies showing wfpb can reverse heart disease [2,3]. These were hospital based studies, but a community-based program using the wfpb diet was developed by Dr. Howard Diehl, called the Coronary Health Improvement Program, and was also shown to have great success on thousands of participants with heart diseases and other diseases. It was so effective on other conditions, that it was renamed the Community Health Improvement Program and is still in use today. It has been described as “achieving some of the most impressive clinical outcomes published in the literature” , for its clinical benefits as well as cost-effectiveness. I only heard of this recently on Dr. Michael Greger’s wfpb site. It’s disappointing that I’ve never seen such an effective program mentioned in the media.
But I think there are misunderstandings about how restrictive wfpb is. It is thought of by many to be close to synonymous with vegan. But looking at the population data that is used to support it , only one out of the five populations is vegan, the other 4 consume varying amounts of animal products and are also quite healthy and long-lived compared to the average citizen on modern diets like that Standard American Diet. It’s true that they all consume a lot less animal products than in the modern diet, the maximum being 15% of calories, with a large proportion of that from fish. Also, the famous diet for reversing heart disease developed by Dr. Dean Ornish  is near-vegan. But Dr. Ornish himself, in his book The Spectrum, points out that while the near-vegan form has been shown to work for reversal of coronary artery blockages, it’s not necessary to be as strict for those of us just trying to stay healthy. Dietician Sharon Palmer also points out that wfpb can be used in a range from vegan to “plant based omnivorous”, in her excellent book The Plant-Powered Diet: The Lifelong Eating Plan for Achieving Optimal Health, Beginning Today.
The other misconception is being overly strict about “whole foods”. This does not mean just organic produce from a farmers market. It might be better to say “minimally processed” which lets in frozen foods. Tofu is a processed food but the process is simple enough to do in your kitchen with cheesecloth if you know what you are doing. Textured soy protein, used in many commercial products, is extruded at high heat and often the chemical hexane is used in the process. Whether this is a health concern is controversial, but this is starting to sound like we’re getting further away from minimally processed. Guacomole or store bought hummus? If somebody just mashed the avocados or chickpeas for you and through in some spices, that’s minimally processed in my book. There’s some concern we may get some bpa exposure from the lining of cans, but you can also look for “non-bpa lining” on cans if you’re worried about it. I’ll take a can of Amy’s split pea soup as “minimally processed” any day over a tv dinner with a bunch of ingredients I can’t pronounce. You get the idea.
Wfpb is also thought of as low fat. Some versions, like those of Dr. Ornish and Dr. Caldwell Esselstyn [2,3[ and Dr. John McDougall  are very low fat. But other authors like Dr. Michael Greger and Dr. Joel Furhman [6,7] enthusiastically endorse whole plant based sources of fats like avocados and nuts, and don’t specifically recommend a fat or carb percentage. Sharon Palmer  agrees, and further emphasizes that mainstream nutrition is going away from recommending specific percentages of fat and carbs, a point also made by Dr. Christine Rosenbloom in .
Carbs vs. fat in the wfpb diet can be adjusted quite a bit by trading grains and starchy fruits and vegetables for higher fat foods like nuts, seeds, and avocados. Some of the healthy populations mentioned above eat as much as 80% of their calories from carbs and only 10% fat, while others are eating more of a moderate carb, moderate fat diet more similar to the Mediterranean diet.
While most wfpb authors consider whole grains to be an important component of the diet, it does not need to constitute a high percentage of your calories. For example, one of the healthy populations mentioned above is the Ikarians, who consume only 4% of their calories from grains and 7% from legumes . And of course there are people with Celiac disease or less severe gluten intolerance who should avoid grains with gluten and use gluten-free grains or pseudo-grains instead, described at length in The Plant-Powered Diet. A reduced grain (and possibly legume) version of wfpb is not that different from a flexible version of paleo that is not too high in meat, as I’ll discuss below.
To learn more about the specifics of the wfpb diet, I recommend The Plant-Powered Diet: The Lifelong Eating Plan for Achieving Optimal Health, Beginning Today, as well as How Not to Die, by Dr. Michael Gregor, and Eat to Live, by Dr. Joel Fuhrman. There is also a wealth of science-based nutritional info on Dr. Gregor’s website.
First I’d like to point out that, in my opinion, all four of the diet alternatives presented in the mainstream nutrition book Food and Fitness After 50 are equivalent to wfpb, if you interpret “whole” and “plant-based” in a flexible manner as discussed above. Now lets look at how some specific diets fit in.
The vegan, or 100% plant food, diet is a subset of wfpb if it is properly formulated. There are many foods that are vegan that are not whole foods, like oreos, soda, french fries, and beer. A vegan diet that includes a significant amount of foods like those is poorly formulated and is not recommended. But the vegan version of wfpb is healthy, as exemplified by Seventh Day Adventist vegans, who are among the healthiest populations in the world [1,10].
The Mediterranean diet is patterned after by the eating habits of Greece, southern Italy, and Spain in the 1950s , and includes high consumption of olive oil, legumes, unrefined grains, fruits, and vegetables, moderate consumption of fish, dairy products (mostly as cheese and yogurt), and wine, and low consumption of non-fish meat foods3. Modern followers of it get up to 70% of their grain consumption from refined grains, which have a relatively high glycemic load , and this does not fit in with wfpb.
Also, many people have the misconception that olive oil is what makes the Mediterranean diet healthy, and they can just indiscriminately pour it on their food. When you are eating lots of bread at an Italian restaurant, it does not make it “healthy Mediterranean” just because you dunked it in olive oil. There are authors proposing health improvements to the Mediterranean diet  that reduce consumption of the foods that are not whole foods, and in this form it is a subset of wfpb.
Some wfpb authors like Dr. Caldwell Esselstyn  and Dr. John McDougall  advocate tuning wfpb to the low end of fat content. Dr Esselstyn promotes the low-fat version because his primary concern is reversing heart disease. Other people, who are highly carb tolerant (typically those who are lean and active), may also thrive on this version.
Low fat is a disaster if done improperly, especially if you are eating lots of refined carbs. But low fat has an advantage if you are sticking to good carbs and are carb tolerant, so it does not cause cravings: It is nutrient dense but not calorically dense. You can get full, and get a lot of nutrition without eating a lot of calories. This was the point of Dr. Dean Ornish’s book Eat More Weigh Less. This only works with good carbs, as the US population should now be well aware, having gone through the “Snackwell” low-fat era where many people thought it was ok to eat all the pretzels, cookies, and ice cream they wanted as long as they were low fat.
“Outside The Mainstream”
Mainstream nutritionists seem to be still a little dubious about diets like paleo and low carb. I am not qualified to recommend them, nor can I comment from personal experience, aside from a brief use of low carb discussed in my eating story. But I have read about them with an open mind and tried to gather information about the science behind them which I’ll review here. Also there are some important tips on making them as healthy as possible. There’s a difference between eating a big slab of meat with a side of mashed sweet potatoes and eating a big salad with lost of healthy greens with some strips of meat thrown in.
This diet is based on evidence that traditional pre-agricultural populations were robust and healthy compared to people in agricultural civilizations, which I’ll discuss in detail in a future post. Hunter gatherers ate a variety of plant foods plus animal foods like meat and fish, but little or no dairy, and some grains although probably considerably fewer than in the typical modern diet. There was not one single version of the pre-agricultural diet. Hunter gatherers ate different proportions of plant vs. animal foods depending on which environment they found themselves in around the world.
The most famous version of paleo is relatively high in consumption of animal products (except dairy), see for example, Dr.Loren Cordain’s The Paleo Diet. Many people do well on this version, but there are some long-term health concerns expressed for excessive consumption of meat and excessive protein (which we’ll also get to in a future post). Admittedly, how much constitutes “excessive” is controversial. Also, authors like Dr. Cordain are meticulous about recommending details of the diet that make it both alkaline and anti-inflammatory, both of which important for long-term health and possibly cancel out any negative health effects of higher consumption of meat.
But some paleo authors are less rigid in their interpretation. For example, Rob Wolf has a recent book Wired To Eat on the subject of personalized nutrition, and argues that paleo is not “one size fits all”. In this flexible form, paleo is more like “no dairy, minimal grains”. And not all paleo advocates are still saying to avoid legumes. There is definitely evidence of their consumption by hunter-gatherers, although some authors still express concern over them containing phytates and lectins, which we’ll go over in detail soon. As Rob points out, though, many people have digestive intolerance to grains (the most well-known being gluten sensitivity), and others have problems with legumes, which are in the “fodmap” category.
If you find you can tolerate and enjoy legumes, or some legume-based products like meat substitutes, then it is straightforward to dial back the percentage of calories from animal products in the paleo diet and replace some of them with legume-based foods. This can even be done without legumes with some non-grain, non-legume foods that are high in protein like buckwheat (which is neither wheat nor a grain, it’s a seed) and mushrooms. I recommend Rob Wolf’s Wired To Eat as a start for more information on a flexible paleo diet, especially if you think you might have intolerance to grains or legumes.
If we tune a flexible version of paleo to the lower percentage of animal foods, there is considerable overlap with wfpb. If you do eat a higher-meat version of the paleo diet, I recommend carefully following the details in books like The Paleo Diet about keeping it alkaline and anti-inflammatory, like emphasizing lots of healthy plant foods.
Proponents of low-carb diets aggressively try to minimize blood glucose spikes. They emphasize eating good carbs, as does wfpb, but argue that there is additional benefit if all carbs are restricted. The main reason presented is that carbs, especially bad carbs, can cause a blood glucose spike leading to metabolic problems as well as cravings and overeating, as discussed previously . In my opinion, the most important use of low-carb may be as a short-term reset to our metabolisms to eliminate these cravings as we saw.
But as discussed there under “carb tolerance”, it is not clear what percentage of the population needs to keep all carbs low, long term, as long as their metabolisms have been “reset” and bad carbs are avoided. We also saw you can find this out for yourself after the reset.
In the last 20 years or so, a significant amount of research has been done on the health and effectiveness of low-carb diets, and various short-term metabolic health benefits have been found .
Some long term studies showed low carb was associated with significantly increased risk of all-cause mortality if the diet was animal-based (emphasizing animal sources of fat and protein), but had a decreased risk of mortality if it was vegetable-based (emphasizing vegetable sources of fat and protein) [15,16,17]. Long term low carb is also associated with increased risk of type II diabetes, but again only if the diet is high in fat and protein from animal foods . If a moderately low carb diet emphasizes plant sources of fat and protein, it is equivalent to wfpb.
I recommend What the Fat?: Fat’s In, Sugar’s Out: How to Live the Ultimate Low Carb Healthy Fat Lifestyle if you want to read up on low carb. It is a collaboration among MD Dr. Grant Schofield, dietician Carol Zinn, and Michelin Chef Craig Rodger. This is a good book to learn about low carb eating, that emphasizes healthy low starch plant foods and other good carbs, as well as healthy fats. The authors point out that people vary in how insulin resistant they are, and as your insulin resistance goes up, your carb tolerance goes down. It was in their book that I also learned about genetic differences among people in starch tolerance, as discussed previously. And it was the low-carb diet from this book I temporarily followed that “reset” my own metabolism as I mentioned in my eating story. [update 05/13/21]: My main disagreement with the book is the authors do not consider the possibility that insulin resistance, and therefore carb tolerance is changeable. There is ample evidence that it is, for example in the book Mastering Diabetes, discussed here, and How Not to Diet, discussed here.
This book is part of a trilogy. The 2nd book is about low-carb for athletes, and the 3rd is about fasting. All 3 are very useful and interesting books.
The ketogenic diet is a very low-carb subset of low-carb. “Keto”is popular right now, You can see signs proclaiming foods to be “keto friendly” in grocery stores. Ketogenic diets intentionally keep carbs very low to induce ketosis, a survival mechanism the body uses to supply fuel to the brain when not enough total calories or calories from carbs are available in the diet- the brain cannot use fat as fuel, it can only use glucose or the alternative fuel “ketone bodies”. Ketosis is called nutritional ketosis when it is intentionally induced by a diet, and such diets are called ketogenic.
The term “ketogenic diet” was coined by Dr Russel Wilder, at the Mayo Clinic, who first used it in 1921 to treat patients with epilepsy. It still plays a useful role for that purpose and for some other clinical conditions. More recently it has been shown to have therapeutic use for other conditions including obesity, neurological disorders and cancer .
The diet is discussed in detail The Art and Science of Low-Carbohydrate Living by Drs Jeff Volek and Stephen Phinney, who have done pioneering research on this diet, on both its general health aspects and its effect on athletic performance.
The most famous diet that uses ketosis is the Atkins diet, and it only uses it short term (about 2 weeks) for its induction phase. This is actually quite similar to a reset and transition. In the induction phase you are in ketosis, which functions like a reset to your metabolism, then you add a bit more good carbs back in, and stay in a non-ketogenic low carb phase while losing weight. After reaching your goal weight, you gradually add more carbs, stopping if any weight gain occurs. This might sound very similar to the “reset and transition” I discussed previously. In fact, it is. The difference is that Atkins diet uses a very strict low-carb “reset”, vs the version presented here which is moderately low carb. And in the transition the Atkins diet has you up your “good carb” content until you start regaining weight, while here we emphasized watching out for cravings returning. As I’ll discuss in my next post, I think the emphasis with any way of eating should be on achieving health improvements, with weight loss as a possible byproduct, not the primary outcome, which is what the reset/transition does. But the Atkins approach could easily be modified to do that also: Do the ketogenic induction phase, then follow the non-ketogenic low-carb version till cravings are gone, then start adding carbs back in, emphasizing good carbs, and stop if cravings return.
It is possible not everyone will respond to a moderately low carb reset as presented here and in the previously mentioned book Always Hungry? Perhaps if your metabolism is more severely dysfunctional it would need a “bigger hammer” to get it back on track, and following short term keto as in the Atkins diet may function well for that purpose. I don’t know what mainstream nutritionists will make of all this, so remember I’m an outsider to the field looking in, just noticing where I see overlap. I did find an important study where keto was successfully and safely used in precisely this manner, 20 days of the ketogenic diet followed by months of a Mediterranean diet. There was good compliance, and good outcomes on health risk factors (such as cholesterol, triglycerides, blood glucose, etc), with no deleterious side effects. And the subjects also happened on average to lose more than 20% of their body fat .
Some aspects of the original Atkins diet and keto, like allowing liberal amounts of saturated fat and processed meats, are still controversial. But the diet can be followed while avoiding those controversial foods, and after the short term induction it could be followed in a form that reduces consumption of animal products (in this form it has been referred to as “eco-Atkins”). This is more similar to wfpb, but tuned to the lower end of the carb spectrum.
Many authors propose using keto only short term or intermittently. But more recently some authors are proposing using the ketogenic diet for a much longer period . I don’t understand the need for it except for the therapeutic reasons mentioned above, because even people with low carb tolerance could start with keto then switch to low-carb non-ketogenic long term, as we saw in the successful keto/Mediterranean combination mentioned above. I haven’t seen scientific studies in support of the health of eating keto long term, and invite comments if I’ve missed anything.
On the contrary, in addition to the health aspects about low-carb diets in general discussed above, there is some evidence of deleterious effects specifically of the ketogenic diet if used continuously long-term. Most of these studies are on patients being treated over a period of multiple years for epilepsy with the diet. Adverse effects include signs of vascular damage and increased arterial stiffness , cardiac complications , and symptoms of bone demineralization (increased risk of kidney stones and high calcium levels in the blood) . What I don’t know of is these same effects would occur if the diet had a higher percentage of plant-foods (emphasizing plant-based fats like avocados) and low-starch fruits and veggies were stressed. We saw above that some deleterious effects were seen for low carb in general, but only if it was high in animal-based fats and protein, not plant-based.
The concern of doing the keto diet incorrectly is high because it is “in” right now, and less qualified authors are jumping on the bandwagon. Two important caveats are: make sure to spend your limited carb budget on healthy foods like greens and berries, and take steps to keep the diet alkaline. This is discussed in detail on Dr. Anna Cabeca’s website. Her website also clears up various misconceptions about keto, like confusing ketosis with keto-acidosis (the latter is a dangerous complication of disease, not the same as ketosis).
All of the alternatives discussed above have one thing in common if properly formulated: They follow the no-junk guidelines.
Sorry I kept having to say “in a future post”, but I wanted this to be more of an overwiew. The next 3 posts on nutrition will be the promised “future posts”, providing background evidence supporting claims here, as well as more detail:
- Health Aspects of Controversial Plant Foods
- Health Aspects of Animal Foods
- Pre-agriculture Nutrition
Before I get to those, my next post will cover a very important topic: I think it’s vital that we get the emphasis off weight loss and onto health, as discussed in Harriet Brown’s excellent book Body of Truth: How Science, History, and Culture Drive Our Obsession with Weight–and What We Can Do about It. I am very grateful to my fellow blogger who brought this book to my attention, the most important thing I have read in a long time. Stay tuned…
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