Here’s my most concise definition of what it means to eat healthfully.

Eat animal foods and properly prepared starchy whole plant foods. Anything else is optional. Given sufficient animal foods, even the starchy plant foods are optional.

Ok, I know – you don’t believe me. You think that this is laughably simplistic. But I have been thinking long and hard about this, weighing the evidence from countless books, studies, talks and presentations. Have a look at the following sections, where I flesh out the concept a little bit more. I’ll be getting into the weeds a little bit here and there, but it’s largely all common sense stuff. That’s also why I didn’t bother to provide references for anything. As Carl Sagan said: “extraordinary claims require extraordinary evidence”. Well, my claims may run counter to the currently established dogma in the field of nutrition, but at the core they are hardly extraordinary. Did the child need to provide references when pointing out that the emperor was naked?

What about leafy greens, vegetables and fruit?

To make a (very) long story short, during the last 150 years nutrition has slowly but steadily been put “on its head” by a powerful, religiously motivated movement which we today call Veganism. Although only a very tiny part of the population, globally or in any particular country, identify as vegans, their influence has been very strong, particularly in the US.

In essence they swapped plant foods and animal foods. Prior to this coup it was well known that animal foods are the most nutritious, while plant foods are inherently inferior. This didn’t sit well with the 7th Day Adventist Church, which preached that eating meat was sinful. So they chose to promote plants, especially cereals, whole grains, vegetables and fruit as the actual health foods and demonised meat and, by extension, all animal food. Today their influence reaches far and wide, influencing national guidelines as well as best-selling books on nutrition. Since this has been going on for several generations, the misinformation is now fully integrated in common knowledge – everybody “knows” that broccoli is more healthy than steak. But is it really?

Animal foods are nutritionally complete (plants are not)

Animal foods contain all the nutrients we need. This includes all essential nutrients as well as those which are sometimes called “conditionally essential”, meaning that although the body can manufacture them from other (essential) nutrients, we are much better off eating them instead of manufacturing them. Some animal foods are more nutrient-rich than others, for example liver is more nutritious than steak, eggs are more nutritious than chicken breast. But in general, someone eating only a variety of animal foods and no plants, they would get all the nutrients they need, whereas someone eating only a variety of plant foods and no animals would develop nutritional deficiencies. Vegans will object, but while it is true that if you combine the foods really well you can get most of what you need, some supplementation will still be necessary (B12, EPA, DHA), and achieving this perfect mix of nutrients is quite laborious and expensive.

Plants contain a lot of nutrients we do not need

The most useful nutrients which plants contain and animal foods do not (with the exception of dairy and honey) are starch and sugar, which we can use for energy. This is why properly prepared starchy plant foods like grains, legumes and tubers as well as fruit are staples in (pre-)historic hunter-gatherer diets.

But what about the vitamins, minerals, phytonutrients and polyphenols which plants contain and animal foods do not? This is the main nutritional argument in favour of plants over animal foods. As it turns out, there are no good reasons to assume that humans benefit from these compounds. Vitamins and minerals are great, but animal foods contain those as well. Fresh meat even contains vitamin C, a vitamin previously thought only to occur in plants. The benefits of phytonutrients and polyphenols have not been demonstrated conclusively. 

Plants contain potent anti-nutrients

Oxalate, gluten, lectins, phytic acid … plants, with the exception of fruit, contain many nutrients which are harmful to humans. Some of them can be neutralised or reduced by proper preparation, like soaking grains in water or often simply by cooking. But considering that those techniques are relatively recent acquisitions in our evolutionary history, it makes no sense to assume that our health is based on consuming foods like kale and broccoli. Those foods would have been hard to find in our environment in meaningful quantities, hard to chew, difficult or even impossible to digest, and overall not a positive contribution to our health.

So plants are off the table?

No, the key takeaway is that plants are optional and meat is the base of healthy nutrition:

  • Perverted common wisdom: Plant foods are the foundation of a healthy diet
  • Actual reality: Animal foods are the foundation of a healthy diet

Vegan influence is trying to convince you that since meat is evil, you have to eat a lot of different plants to somehow replace all the nutrition you lost by cutting out or reducing animal foods. When you decide to ignore this plant-based influence and base your diet on meat, you can still eat some vegetables and fruit along with the meat. But keep in mind that those foods are very recent additions to our diet and may have a negative impact. Some people have no problems with a diet that contains some animal foods and starch and a lot of vegetables and fruit. Others do best with mostly animal foods and a little bit of vegetables or fruit. Yet others do best with no plant foods at all. Remember that this is all consistent with the fact that animal foods are the most nutritious food there is.

If you have never tried a largely meat-based diet and you’re struggling with obesity, diabetes or metabolic syndrome, or you have allergies or digestive problems, consider giving it a try for a couple of weeks and see how you feel. It might change your life! Even if you don’t stay 100% carnivorous (few people do), maybe you’ll improve simply by realising that your previous notion of plants being healthy and meat being dangerous was completely wrong. And that means that you’ll not only be able to consume foods like steak, eggs, butter and cheese with more confidence and no feeling of guilt, but you also won’t feel too bad for not “eating your greens”.

So what is off the table?

You shouldn’t eat processed food on a daily basis, especially food combining flour, sugar and seed oils. This simply follows from the one rule laid out above, since this combination is almost opposite to the template of animal foods and whole starchy plant foods. Some people avoid these foods completely and almost religiously. I don’t, in fact I eat them regularly. It’s a matter of quantity and frequency. As long as my diet is 80-90% “clean”, I can get away with the occasional transgression, and this makes the diet much more doable.

Another thing to keep in mind is to avoid, on a meal by meal basis, combining fat and carbs in almost equal ratio. So any given meal should be either fat based (typically carnivorous, fatty meat with some optional vegetables) or starch based (some lean meat with potatoes, rice, bread, vegetables).

But What About The EnviRonment?

If you care about the environment, your number one priority should be to reduce the consumption of fossil fuels. Global warming, plastics, pesticides … those are all downstream of fossil fuel. You may have heard stories about meat, especially beef, being the biggest offender in all of agriculture when it comes to greenhouse gases. Not true. In fact, a local grass-fed cow is not only carbon neutral, but carbon negative, meaning that it helps to fight global warming! This is because every carbon atom that the cow emits in the form of carbon dioxide or methane was previously absorbed from the atmosphere by the grass. So the cycle is neutral, and can even be negative depending on what else is fed to the cows. Water consumption is another big argument by Vegans, but that’s a non-issue as well since most of that water is rain water falling on the grass. It’s not drinking water. Lastly, in comparison to plant-crop production, pastures with grazing cows prevent top soil erosion and require no fertilizer or pesticides.

But What aBout Animal Welfare?

As much as Vegans hate to hear it, animals die for our food production regardless of what we eat. Take wheat as an example – not only are many animals displaced and killed when a patch of grassland is converted to wheat crops, but countless insects and rodents die from the pesticides, plus all the small animals which die during harvesting.

Of course we should all strive to minimize needless animal suffering in animal food production … but the right way to do it is not to eliminate animal agriculture, but to optimize it. Eliminating it would have all sorts of negative consequences, both for the planet because of topsoil erosion and for us, because of malnutrition.

How can we optimize it? We should eat big ruminant animals which are raised in their natural environment, which is grazing on grassland or in forests. We can supplement that with pigs and chicken/eggs, but the bigger the animal, the less have to die to produce the same amount of food. Interestingly red meat from ruminants has been shown to be the most nutritious for humans, which, as a bonus argument, is confirmed by most cave paintings which don’t depict humans hunting broccoli or tofudebeasts, but antilopes, buffaloes and elephants/mammoth.

Fat + Carbs = Diabesity

Does it matter where we get our energy from? “A calorie is a calorie”, many experts say, and the food industry has been happily endorsing that mantra for decades. Doesn’t matter whether you are eating broccoli, chocolate, bread or beef … it’s all just calories. Or is it?

No. You know that what you eat has huge implications. Why else would we be so particular about the foods we eat? The body is a biochemical laboratory, constantly metabolizing (burning) food for energy. The metabolic pathways for our major energy-yielding macro-nutrients (fat, carbohydrate and protein) are very different. When you eat 1,000 calories of either sugar or fat, while the amount of energy is the same, different chemicals are produced while metabolizing the food, and different configurations of various hormones and enzymes ensue.

Since of the three macro-nutrients protein is primarily used as building material, we can focus on the two remaining macronutrients, fat and carbohydrate. We are left with three basic strategies:

Fat Based Diet (Low-Carb)

This is the primal/keto/carnivore approach. The body optimizes its metabolic pathways for burning fat, including the production of ketones. This strategy is well suited for body-fat loss and lean body maintenance. People on this diet will tend to eat fewer meals, since the body is used to accessing its fat stores efficiently when there is no food “coming in”.

Typical meal options using whole foods: Steak/fish/eggs and vegetables/low-sugar fruit.

Carb Based Diet (Low-Fat)

This is the typical plant-based/vegan approach. Little or no meat is consumed, or at best only lean meat, and as little fat as possible. While this is certainly compatible with optimizing body composition, it is more difficult to maintain for most people, and prone to developing deficiencies. On this diet people will gravitate towards eating more frequently throughout the day, since the body is not used to burning fat efficiently. As soon as the carbs from the last meal are used up, without ketones in the system to fuel the brain it senses an energy crisis, prompting its “user” to eat again.

Typical meal options using whole foods: Salad with low-fat dressing and bread, oatmeal, cereal, fruit salads or smoothies.

The ”Balanced” Diet (Moderate-Fat, Moderate-Carbs)

This is the standard “Western” Diet. While some people might be able to stay lean on a “balanced” mix of carbs and fat, most people will find it difficult not to overeat calories, since mixing carbs and fat not only maximizes the energy content of food, but also makes them hyper-palatable. Some research also hints towards unfavorable effects on blood lipids when saturated fats are consumed in a high-carb setting.

Typical meal options using processed foods: Burgers and chips/fries, pasta and cheese, donuts, cakes, ice cream, pizza, chocolate, peanut butter and jelly sandwich

Typical meal options using whole foods: Fatty meat/fish/eggs and (sweet) potatoes, nuts and (dried) fruit

So are carbs evil?

Yes, if you eat them with a lot of fat.

So is fat evil?

Yes, if you eat it with a lot of carbs.

But saturated fat is surely always evil?

No. When you eat saturated fat, what happens to it depends heavily on two factors: whether you are overeating, and the presence of carbs. If you are not overeating and few carbs are present, the saturated fat you eat will swiftly be burned for energy by the body, no harm done. On the other hand, when you overeat and mix saturated fat and carbs, it may linger in the blood stream and cause undesirable effects. So: Steak and butter is ok, but not if you add a big baked potato.

Isn’t it enough to cut out sugar?

No. Granted, a no-sugar diet avoids many bad foods. But if it still contains carbs and fat, the body is probably still confused. The food sends mixed signals. Carbs are like rocket fuel for the body. Even complex starches are eventually broken down to glucose, which must be burned for energy immediately. Simultaneously you are giving the body slow-burning fat.

So what do I do if I currently eat a 50:50 diet?

The worst you could do would be to eat more fat on top. Fat is healthy only if you make it the main source of energy in the diet by simultaneously cutting out carbs. The second worst thing you could do is to eat more “healthy” carbs on top. The key is to pick one major source of calories – either fat or carbs – and then to implement your diet using foods rich in protein and micro-nutrients.

How does this principle of not mixing fat and carbs align with evolution?

Quite well! Think about the kind of foods which were available to humans hundreds of thousands of years ago: Whole plants and animals, basically. What do all of them have in common?

None of them are mixtures of fat and carbs. Most plants contain almost exclusively carbohydrate, except for nuts, seeds and some special types of fruit like avocados and olives, which contain predominantly fat. Meat, fish, eggs and other animal foods are basically protein and fat without any carbohydrate. Milk is an exception, since it contains a mix of carbs and fat. It exists specifically for the purpose of supporting growing babies, so it is the one whole food that is not appropriate for our purposes. But that is in line with evolution, since humans have been eating milk for a very short time, even today there are many populations which are predominantly lactose intolerant. We can still eat high-fat or high-protein dairy though, in which the lactose has been largely removed.

So does that mean that I have to be either carnivore or vegan?

No. Granted, fat and meat are a natural match, as are carbs and plants. But it is possible to do a fat-based vegan diet, based largely on nuts, coconut, olives and avocados. The other extreme, a carbs-based carnivore diet, is of course not possible. Maybe if you ate only skim milk and whey protein … which is hardly sustainable.

Of course various combinations of animal and plant foods are possible. Fatty meat and vegetables is very popular, on the carbs-heavy side one could eat lean meat, vegetables and pasta or rice, which is the basic blueprint of “clean eating”.

With the focus on fat vs. carbs, is protein irrelevant?

Not at all. In fact, protein is absolutely crucial. In order to thrive, we have to continuously eat at least as much protein as the body is breaking down. On a fat-based diet we need to eat even more protein, since the body uses some of it to generate glucose through a process called gluconeogenesis. Age is also a factor: the older we are, the more protein we should eat, since the body breaks down more tissue and struggles more to replace it.

One useful rule of thumb is to eat at least 2 grams of protein per kg of your ideal body weight each day.

Ha! Gotcha! Why not just eat the carbs rather than getting them via gluconeogenesis?

Not so fast. Remember that the context for gluconeogenesis is a fat-based diet. Such a diet works only well when the body can burn its fat stores efficiently. In order for that to happen, carbohydrate intake needs to be very low. This causes insulin levels to drop, and glucagon levels to rise. And only this rise in glucagon enables the liver to produce ketones and fine-tune blood sugar by producing glucose from protein exactly when needed, and in the amounts required.

But glucose is the preferred fuel for the body!

Yes and no. Yes, the body preferentially burns glucose rather than fat. But why? Maybe another nutrient serves as a good illustration: alcohol. Turns out that the body burns alcohol even before glucose. Does that mean that we are meant to run on alcohol? No, it means that alcohol is a poison, and the body tries to get rid of it as fast as possible. It is similar with glucose. It is a poison if present for too long, and in high concentrations.

“Preferred” is not a good criterion for choosing what to eat. We should rather ask ourselves which macronutrient our body uses to store energy. That is the energy source our body uses as a default when we, for whatever reason, don’t eat for a while. And this default fuel, fat, is what we should probably prefer to eat.

In the end, which is superior – fat or carbs?

That depends on who you ask. The jury is still out. But having tried both, I prefer the fat-based approach. The big drawback is the social pressure you face for not eating carbs and skipping meals. But the improved satiety and digestion are huge advantages. If you add exercise to the mix, you can get away with some transgressions – for me mainly chocolate and fruit, occasionally. I gave the plant/carbs based approach a chance a few months ago, but I finally gave up. I actually like the foods a lot – muesli, plant milks, fruit, beans, bread, whole-wheat pasta, tomatoes … taste-wise it was not a problem at all. Digestion was horrible though, and I felt hungry all the time. On the other hand, when I eat mostly meat everything is easy and awesome without much optimization at all.

An All Meat Diet -Why Not?

Today I came across this news article:

Please do not try to survive on an all-meat diet

It made me a little bit angry. Before I tell you why, let me point out that I am currently not on a 100% meat diet, and while I won’t rule out the possibility completely, it is unlikely that I will go on such a diet in the foreseeable future. I am however on a diet heavy in (red) meat, and I’ve read many, many articles, studies, blog posts and tweets on the topic. I’ve heard vegans bash the diet, carnivores recommend the diet for all sorts of reasons including some miraculous claims, I’ve heard mainstream scientists advising against it, and I’ve heard just normal people ridiculing it, demonizing it or praising it.

TL;DR: A 100% meat diet could be perfectly fine, there’s no reason why it by definition can’t work or would make you sick. That doesn’t mean that everybody should be on it. Some people might thrive on a diet low in meat, others might do best on a primal style diet which is high in meat but also includes some vegetables and fruit.

Let’s go through my biggest beefs (silly pun intended) with the article one by one.

 […] the proponents of the carnivore diet, including Shawn Baker, a former orthopedic surgeon […] [who] had his medical license revoked in 2017 in part for “incompetence to practice as a licensee”.

This is a good example of a combination of an ad hominem attack and quote mining. Yes, Dr. Baker had his license revoked, but the reason was that he wanted to suggest to some of his patients that instead of having their arthritic joints replaced, they might consider changing their diet first. His employer (a hospital) saw that as a conflict of interest (surgery is much more lucrative than nutrition counselling), so they found a way to strip him of his medical license in order to lay him off more easily. This is quite different from him being just an “incompetent” doctor. In fact, he is about to get his license back, and his competence as an orthopedic surgeon is not really in dispute. In any case, all of that has nothing to do with anything he says on the topic of nutrition.

Mikhaila Peterson has absolutely no scientific or medical qualifications, and while her father may be a psychologist, he has no training in nutrition.

Those two prominent advocates of the carnivore diet indeed have no training in nutrition. Which does (or at least should) not mean that they cannot speak on the topic. As long as they don’t claim to be certified nutritionists or dieticians (which they never did), nothing is wrong with them promoting any type of diet.

You need 13 vitamins in order to live, and though you can actually get most of them from eating a variety of meats, you’re going to miss out on some crucial ones if you totally forego flora. Folate, along with vitamins C and E, pretty much only come from veggies, mostly green leafy ones and citrus.

No. Dating back to Steffanson’s  famous experiment, it has been well documented that people can survive and even thrive in good health on a carnivorous diet without eating any plants. Fresh meat actually contains some vitamin C and the amount the body needs goes down when no carbohydrate is ingested. Vitamin E is an antioxidant first and foremost, and although to my knowledge no studies exist on it, the demand also seems to go down on carnivorous diet. Baker speculates that without the constant intake of plant foods the body makes more of its endogenous anti-oxidants like glutathione. None of this is proven scientifically, but as I already mentioned, none of the proponents of carnivory claim that it is.

This is why sailors used to get scurvy—not enough vitamin C in their largely fish- and other-meat-based diets.

These sailors actually got scurvy because they ate neither veggies/fruits nor fresh meat. They ate mostly dried meat (which actually contains no vitamin C) instead of fresh meat, hence the scurvy.

Plus, if you don’t get enough vitamin E your body can’t use vitamin K as well […]

No scientific study is provided to back up this claim, and since we need vitamin K for example to optimize calcium usage in bone and teeth growth and that is not an issue for people on the carnivorous diet (rather the reverse), we can at least speculate that on such diets the body may need less vitamin E. Since it is an anti-oxidant, and a 100% meat diet is by definition low in oxidative stress, this does not seem all that implausible.

And then there’s the issue of fiber. Meat has no fiber, yet we know that fiber is crucial to a healthy diet.

Ah, abeautiful example of an “just so” argument. In fact we don’t know at all whether fiber is needed or even useful in general. There are many studies which show a benefit with increased fiber intake for some hard outcomes, but it always depends on what people eat with the fiber. It appears like fiber acts as an antidote to processed food. For example, if you eat nothing but low-fiber cereal and skim milk, you might be more prone to diabetes and metabolic syndrome than if you eat high-fiber cereal. But what about people who eat no junk food at all? I don’t know any high-quality studies which show benefits of fiber in that type of situation. On the other hand there are studies which show that fiber causes digestive problems in many people, aggravating conditions like diverticulitis, Crohn’s disease and IBS. Which makes sense – when someone has a sick colon, increasing the amount of indigestible plant matter which gets passed through the colon can easily irritate the colon further. A 100% meat diet on the other hand contains no fiber at all, and virtually all the food is digested and absorbed in the small intestine. Which is why such a diet is recommended before colonoscopies and other similar procedures.

The Inuit stay healthy because they eat a wide variety of meats, most of which fad-dieters are not consuming. They stave off scurvy by feasting on collagen-rich, vitamin-C-dense whale skin and other fresh, uncooked meats.

Notice the revealing choice of words “fad-dieters”. The author clearly thinks that an all meat diet is a fad, and cannot resist this bias from showing in this article. First, although many outspoken carnivores say that they’re eating mostly beef, and Mikhaila Peterson pretty much eats 100% beef, many do mix it up. And none of them say that people should eat 100% beef. Also, the author now contradicts herself, establishing that some animal based foods in fact contain enough vitamin C to prevent scurvy. Uncooked meat is the solution to that, which carnivores typically consume – pretty much all of them like their steaks at least medium (rare).

And the flesh [the Inuit] consume often isn’t mostly protein—it’s about 50 percent fat, much of which is of the healthier, unsaturated variety. The meat you buy in a grocery store is largely saturated fat, since that’s the kind that develops on animals who get little exercise and eat mostly corn.

Sigh. No, and no. First, people on a carnivorous diet do prefer the fattier cuts of meat. This makes sense, because a diet which is too high in protein (over 50% of calories) is not sustainable. The meat they typically recommend is rib eye steak, pork chops, or ground beef, which is all reasonably high in fat. Second, virtually all the meat you can buy, independently of whether it is grass-fed, grass-finished or grain-finished, is mostly unsaturated fat. Google that for yourself if you don’t believe me. Dietary fat which is predominantly saturated is either butter or coconut/palm oil. All other sources of fat are predominantly unsaturated, including beef, pork, poultry and fish.

You could, arguably, take supplements for all of the deficiencies that eating only farm-raised animals brings on.

Arguably, supplements are recommended for most diets. They are essential for vegan diets, but on any other diet some people say they are beneficial, some say they are not. It is kind of unfair to single out the carnivorous diet and suggest that it in particular requires supplementation. A few paragraphs above, the author managed to name three nutrients that might be a reason for concern, which really aren’t.

Eating lots of red meat has long been linked to colorectal cancer, along with pancreatic and prostate cancers to a lesser degree. The World Health Organization report on red meats supported that link and backed it up with evidence that, when cooked at temperatures exceeding 300°F, flesh produces certain chemicals that are carcinogenic.

Yes, the red meat “controversy”. Georgia Ede shows beautifully how little cause for concern there is, and how much manipulation and unwarranted conclusions the WHO/IARC drew to arrive at the message which, sadly, has pervaded our society. In fact the (in)famous report showed a tiny increase in relative risk for red mead and colon cancer, which is little more than statistical noise. And that’s not just a rationalization put forth by meat lovers to justify their “unhealthy” habit. If we took every association with a relative risk increase around 20% seriously, we would really run out of food – practically everything would be off the table.

Animal meat also tends to push the balance of our good and bad cholesterol (called HDL and LDL, respectively) toward the bad end. You want more HDL and less LDL, along with low levels of triglycerides. Fatty red meats do the opposite: they raise your LDL and triglycerides while lowering your HDL.

If you replace bread and pasta with any type of meat, studies show that you will actually achieve what the author herself knows is favorable: HDL goes up, triglycerides go down. It has been known for at least a decade that any low-carb diet will have this beneficial effect on blood lipids. LDL does stay high on a largely meat based diet, but this is not necessarily a bad thing – in fact, there are many studies which show that higher LDL is associated with reduced mortality, as long as other, more important markers, like the HDL/triglyceride ratio, are favorable.

What annoys me the most about the current discussions on nutrition is that people can write such blatantly false statements and get away with it without any major outcry.

Again, you could try to combat this by eating less red meat and opting for healthier options, like lean poultry and fish, both of which have more nutrients than beef and seem to generally be better for you. Organ meats from all sorts of animals have plenty of vitamins, which can also help supplement your diet in small quantities. But if all you ever eat is meat, eating just fish and chicken could get pretty monotonous.

Poultry and fish are not “automatically” healthier than red meat, they do not have “more” nutrients. They do have slightly different nutrients compared to red meat, and people might simply prefer poultry or fish over beef. Obviously a 100% meat based diet is going to be monotonous compared to a “balanced” diet, which is why it is not for everyone. Personally I really like beef (steak) the most, but if for someone else pork chops, chicken breasts or salmon is preferrable, then that is fine as well.

This is, most likely, why you lose weight on any diet. Give someone rules that alter their eating habits, especially really strict ones that make it hard to find random things to snack on throughout the day, and they’ll probably end up consuming less overall. Protein is an especially satiating food, so the calories per meal will be much lower than any in which you consume carbs.

Yes, and this effect of intuitive/automatic caloric reduction is portrayed as a bad thing by the author, but it actually isn’t. Think about it: If you are overweight, it is because you are eating too much. And the reason for that is that whatever you are eating is not providing enough satiation – at the end of the day you might be satisfied, but you needed to eat too many calories. Which means that whatever you are eating is not optimal for you. Another diet, which – by whatever means – leads to you being satisfied with fewer calories, might be more optimal. This is why carnivorous diets work for many people – they contain more protein, which is more satiating, which leads to a lower caloric intake naturally, without any additional hunger.

If you’re looking to lose weight, cutting calories is obviously a good thing, but you need to do it in a sustainable way. […] . Nutritionists instead advise that you pick a way of eating that you can maintain for life.

No, cutting calories is not obviously a good thing – you need to find a way to cut the hunger as well. Only that makes it sustainable. The author is correct in pointing out that whatever diet you choose, you should be comfortable maintaining it for life. Carnivory may not be ideal in that regard, but most people manage to do well on a “80% carnivorous” diet which follows a primal template where you eat primarily meat, plus some vegetables and some fruit. Which is what many carnivores recommend as well – very few of them say that only 100% meat works for everybody.

Pretty much any extreme diet is going to be problematic. Fruit may be good for you, but if all you ever ate was fruit you’d end up with serious nutritional deficiencies. Even vegans, who generally still eat a diverse group of foods, have trouble getting certain nutrients like vitamin B12, which our bodies aren’t very good at absorbing from plant sources.

Finally a paragraph which is mostly correct, except that I am sure that there are some people for whom an extreme diet might be ideal. Penn Jillette comes to mind – he thrives on an extreme vegan diet. And Dr. Shawn Baker obviously thrives on a 99% beef diet. Mikhaila Peterson thrives on a 100% beef diet. It’s all fine, as long as nobody pushes their extreme diet onto others.

It’s not flashy, but panels of experts consistently recommend consuming a wide variety of foods, all in moderation. And yes, that can include meat. But you should sneak yourself a few veggies in there when you can.

Well, some people can surely eat “everything in moderation”. Others end up with such severe arthritis on a “balanced” diet that they need to have their hip and ankle joint replaced at the age of 17 (Mikhaila Peterson). I can only say that if these people then end up eating only beef and feeling fine, just accept that as a testament to how different we all are, even though we are all the same species.

How Much Protein Should You Eat?

TL;DR: At least 2g per kg of your desired weight, every day, mostly from animal sources.

This is a really old question that never really goes away. There are many different answers, and depending on which philosophy you follow, which agendas you have, and which books you read, you can end up with very different recommendations. There are some authors who recommend a really low intake of protein, about 10% of total calories. Those recommendations are well below the RDA (recommended daily allowance) issued by the U.S. government, which is 0.8g per kg of “reference body weight”. At the high end of the spectrum you have the body building community, traditionally recommending intakes well above 2g per kg.

So there is this wide range of intakes which people can survive on, ranging between about 5-50% of calories from protein. What is ideal? Does it depend on your goals, your age, your gender? The average intake in modern “westernized” societies is around 14-15%. The average intake in modern hunter-gatherer populations is about 25%.

My suggestion: >30% protein, or >2g per kg of desired body weight, mostly from animal sources!

I’m a big fan of Ted Naiman, who has recently given a great talk on protein intake. He goes through various arguments for and against high protein intake, and basically shows that a) higher protein intakes (above 30%) are not unhealthy and b) improved body composition (more muscle, less body fat) may be easier to achieve on such higher intakes. This is in line with most of the literature I’ve read and agree with. The take-away message is: It’s better to eat too much protein than too little.

There are many books and studies which I could refer you to, but I’ve settled on just linking to this well-respected (and often cited) paper:

Evidence-Based Recommendations for Optimal Dietary Protein Intake in Older People: A Position Paper From the PROT-AGE Study Group

The paper recommends a lower limit of 1.2g per kg of body weight for active people, and 1.5g for those who suffer from acute or chronic disease. That is at least 50% above the RDA (0.8g per kg).

Advantages of Higher Protein Intake From Animal Foods

  • Increased satiety (you stay fuller longer)
  • Positive nitrogen balance (minimal muscle loss, maximum muscle gain)
  • Delicious meals (meat, fish and eggs should be the center-piece)
  • Improved digestion (less bulky plant-matter, more nutrient-dense food)
  • “Automatic low-carb” (more meat/fish means less carb-heavy plant food, if total calories stay the same)

So What Does This Mean Practically?

The easiest way to implement this principle is to incrementally change your diet, replacing low-protein/high-carb foods with high-protein/low-carb animal foods. Like I outlined a while ago in my post about changing one’s diet one swap at a time.

For example, If you really like salads, add a nice serving of meat and in exchange, have less or no bread with the salad. Maybe add eggs and reduce beans/corn.

Extreme Example: Cake vs. High-Protein Yogurt

As a treat, I used to have cheesecake. As it turns out, a little bit of full-fat yogurt, some salt and vanilla whey protein powder emulates the taste nicely. I add some frozen blueberries, and that combination is really, really satisfying and tastes like a combination of blueberry cheesecake and ice cream. According to Cronometer, one serving of Baskin Robbins blueberry cheese cake ice-cream is 273 Calories, with 7% protein, 46% carbs (28g sugar) and 48% fat. This is the worst combination possible: low-protein (5g) plus a 50:50 mix of carbs/sugar and fat.

Here’s my combination of yogurt, salt, protein-powder and blueberries: 31% protein, 18% carbs and 51% fat. 11g of sugar. 21g of protein. So compared to the ice-cream, on an equal-calories basis it contains only 30% of the sugar and carbs, but 4 times more protein. And almost the same amount of fat.

Why Not Use Plant-Based Sources Of Protein?

Typical plant-based sources of protein include low-starch vegetables like broccoli or even kale, and beans/legumes. These foods come with big disadvantages:

  • Low-Starch vegetables surely contain a lot of protein in terms of percent of total calories, but you would have to eat several pounds to get meaningful absolute amounts of protein.
  • Beans/legumes contain a decent amount of protein per calorie, but also a lot of energy in the form of carbohydrates.
  • Both contain a lot of fiber and anti-nutrients which can cause gastro-intestinal distress in many people.
  • The protein in plants is generally less bio-available than that in animals, the human body typically absorbs only 70% of  it. So you would have to eat even more of these sources.

This does not mean you have to stop eating those foods – you just don’t need to eat them for the protein.






Optimize Your Diet One Swap At A Time!

Last week I wrote about how a meat-based diet works, and why it may be a very efficient and healthy strategy for people who are struggling with weight loss. But how to start? Making a huge change in one’s diet is difficult – lots of habits to change, social pressures, worries about whether it’s the right thing to do … there are many obstacles which make it unlikely that a sudden, big intervention will lead to meaningful long-term changes.

Most people eat a small number of foods most of the time. It is those staple meals you should try to focus on. If you manage to eat really healthy 80% of the time, you can relax a bit on the remaining 20%. So let’s see how you could improve those meals one step at a time.

Make Small Healthy Swaps!

Following those simple rules you can make small tweaks (“swaps”) to your meals which will incrementally improve your diet:

  • Replace a part of the meal which is mostly “empty” calories with meat or other animal products. Or just remove it.
  • The relative amount of protein (% of calories) of the meal must increase.
  • The total number of calories of the meal should not increase.
  • The “deliciousness” of the meal should not decrease.

For example, next time you make sandwiches maybe use half as much bread (half as many sandwiches) or thinner slices of bread, but add more ham and maybe an egg, maybe use home-made mayo instead of margarine. Calories stay the same, empty calories from the bread are being replaced with more satiating calories from the meat and the eggs, and along for the ride come nutrients that our body craves and would not get from bread or vegetables. The sandwiches are still as tasty or even tastier, and much more nutritious!

The main goal physiologically is to increase the nutrient density of the meal, which is measured by putting the amount of nutrients (vitamins, minerals, protein) in relation to the amount of energy (calories).

Why Does This Work For Weight Loss And Body Composition?

By optimizing the meals, the body gets more nutrition and thus stays fuller longer. Studies suggest that protein is the most satiating macro-nutrient. If you do it correctly and choose the right foods – some experimentation might be needed – then you end up with a win-win situation: You eat more delicious meals, are less hungry between meals, and if you are also active or exercise a lot, your body has more raw material (micro-nutrients and protein) to repair and improve your body.

Suggestions For Foods To Swap Out (Remove/Reduce Amount)

  • Bread (including whole-grain)
  • Pasta (including whole-grain)
  • Rice (including brown/whole-grain)
  • Cereal (including … you know the deal)
  • Potatoes (including sweet)
  • Oils (especially industrial seed oils, but also olive/coconut)
  • Cake / Pastry
  • Chocolate (especially sweet non-dark)
  • Candy / Sugary Drinks / Juice
  • Low-Fat Dairy
  • Nut/Soy “milks”

Example Foods To Swap In (Introduce/Increase Amount)

  • Meat in all forms (including processed, but “whole” is better)
  • Fish
  • Cheese (focus on higher-protein types)
  • Full-Fat Dairy
  • Eggs
  • Seafood
  • Bacon (avoid high-fat, or keep amount small)
  • Protein Powder (egg/whey/casein based)
  • Protein Bars (depending on how well you tolerate them – beware of sugar alcohols)
  • Water / Diet Drinks

Some Bad Choices For Swapping In

These are foods which some people might be tempted to use as replacements, but are actually as bad as the foods that get replaced, or they are at best neutral and don’t contribute to satiety as much as the other foods above. That doesn’t mean you should never eat them! It just means that they are less obvious choices as replacements, and you should be careful when using them. Reducing the amount works for many people, and/or combining them with the safer choices above.

  • Butter (except in small amounts for frying or as a condiment like garlic butter)
  • Heavy Cream (unless in small amounts and/or paired with protein)
  • Other Oils/Fat (empty calories / no protein, even if animal-based or “extra virgin”)
  • Whole Grains/Fiber (adds little nutrition / protein, leads to bloating in some people)
  • Low-Starch Vegetables (add them on top if you can digest them well, but they add little satiety / protein)
  • Fruit (much sugar, little satiety / protein)
  • Nuts (too many calories, small effect on satiety)


In Defense Of Meat-Based Diets

I previously talked about how to thrive on a vegan diet.  But the opposite approach – a diet heavy in meat – may actually turn out to be best for me, or indeed many people. In this post I will try to outline what I am doing right now, and touch briefly on most of the arguments pro/con a meat based diet, which will then be discussed in much greater detail in future posts.

Disclaimer: This is what I eat – it is not medical advice for you. You can – and should – decide yourself what you eat. For the last 10 years I’ve been reading close to 50 books on the topic, watching countless presentations by experts, examining studies and meta-analyses, listening to podcasts … I’ve considered the opinions of mainstream authors and scientists, naturopaths (ugh), vegans, paleos, doctors, psychologists … to quote one of my favorite TV personas: “It’s a jungle out there!”. I don’t expect you to trust me on anything that I write, except for one thing: Every sentence is not just an opinion I adopted because I saw some isolated headline on the news, but instead the result of this vast process of gathering information and comparing different sources.

Take what you want from this, with a bucket of salt, do your own investigation and then decide what to do. It is your health that’s on the line. Especially if you have a couple of pounds to lose and you’ve never tried a diet like this before, you may want to consider giving it a try.

TL;DR: Meat is perfectly healthy food which humans are “designed” to eat.  In the last 50+ years meat – and animal-based food in general – has been maligned by the media, and science unfortunately took a huge step in the wrong direction in the 1950s with blaming saturated fat and cholesterol for many of the modern chronic diseases. As a result, the mainstream advice for healthy nutrition (a diet based on grains/carbs with some meat, vegetables and fruit) may be the opposite of what is actually healthy.

What Does “Meat-Based” Mean?

There are people who eat 100% meat and nothing else (except salt). The most common labels for this type of diet are “carnivore” or “carnivory”. I define my “meat-based diet” as one where the vast majority of calories (like 80%) comes from meat or other animal products.

Why “Meat-Based” and not “Animal-Based”?

Healthy vegan diets are typically also called “plant-based” – shouldn’t I call my diet “animal-based”? Perhaps, but most people find that for various reasons, having to do with nutrition, satiety and environmental concerns, the staple food on such a diet is red meat from ruminants (cow, bison, sheep). So “meat-based” is a better description of what people eat mostly on such a diet. For vegans, “grain/legume/tuber-based” would be most accurate, or “avocado/nut-based” if they’re doing some form ketogenic diet.

What are the Goals of the Diet?

In a nutshell:

  • Eating to satiety (no hunger pangs or blood sugar crashes)
  • Enjoying the food (delicious meals)
  • Optimal body composition (“look good naked”)
  • Optimal athletic performance (metabolic flexibility, fat-burning)
  • Overall health and longevity (nutritious diet, avoid anti-nutrients)
  • Protect the environment (sustainable (animal-)agriculture)
  • Avoid orthorexia (keep it simple)

Which Foods are “Allowed”?

I think that for any eating pattern to be sustainable it must allow room for exceptions. So instead of outlawing and demonizing certain foods, I will simply list the foods the diet ideally/typically consists of:

  • Red meat from ruminants (cows, bison, sheep)
  • Eggs
  • Dairy (Cheese, Yogurt, Cream, Butter)
  • Fish
  • Poultry
  • Seafood
  • Other red meat
  • Vegetables and mushrooms (low-starch/sugar)
  • Nuts
  • Fruit (low-glycemic like berries and citrus, or very small portions)
  • Salt (liberally)

This list is loosely in descending order of caloric contribution to the diet. This may vary from person to person, for example some people might hate red meat, but love poulty. Some might have allergies or other problems with specific foods. Any combination is fine, provided that 70-80% of the calories are coming from animal food. There is no restriction on salt.

Which Foods are “Forbidden”?

These are foods which are best avoided or at least minimized:

  • Processed food products
  • Grains
  • Sugar
  • Industrial seed oils

Do I Track What I Eat?

Yes, but only occasionally. Every once in a while I will try to track a complete day of eating on Cronometer and check if what I’m eating is in line with what I would intuitively expect.

Are There “Cheat” Days or Meals?

Yes. Sometimes I eat whatever I want, like cake, or ice cream, or even ultra-processed food products. I don’t consider them to be “cheats” though, as long as they don’t undermine the goals of the diet in the long term. This is a “slippery slope” though – some people might do better avoiding these exceptions completely. What definitely doesn’t work for me is the concept of a weekly cheat day. A chocolate sundae every month might be a good solution for some people. If nothing else, consider these exceptions an antidote to orthorexia.

How Could Someone Transition Into This Diet?

Either change everything at once (difficult, but fast), or make simple swaps that reduce carbs and increase protein and fat:

  • Two slices of bread + two slices of ham
    => one slice of bread + two slices of ham + 1 slice of cheese
  • A sandwich or a burger
    => eat everything except the bread, or order without the bread so to waste no food
  • Steak, vegetables and a boiled potato
    => Steak, vegetables, garlic butter + avocado
  • Carb rich cereal bar
    => low-carb protein bar
  • Grain based breakfast
    => eggs and bacon or left-over steak
  • French fries on the side
    => low-carb veggies or salads on the side
  • Bread on the side
    => extra meat or cheese
  • Cake for dessert
    => Berries for dessert
  • Ice cream
    => (full-fat) yogurt without added sugar + berries

In each case you are not necessarily trading a deadly poison for a perfectly healthy food, but you are improving things however slightly, increasing your intake of protein from meat and decreasing your intake of empty calories, particularly from carbohydrate, which your body has no choice but to immediately burn for enery or store as fat. Total energy stays roughly the same, and satiety increases, since protein is ultimately the most satiating macro-nutrient.

What Are The “Macros” On This Diet?

Many people think of diets in terms of macro-nutrient distribution – as you may know, there are basically three macros: Carbs, Protein and Fat. Technically those all provide energy (calories). However, protein is special because the body uses it primarily as a  structural material.

Since one of the goals of the diet is to optimize athletic performance and body composition, it aims for a much higher protein intake than the average in western populations of about 14-15% of total calories. A better way to quantify intake is in relation to body weight. I aim for about 1.5-2g per kg of desired body weight, while the common recommendation is 0.8g per kg. This puts me at around 30-40% of total calories, or twice as much as the average intake. The bulk of my calories come from fat – that follows automatically from the selection of foods preferred on the diet, which are all low in carbohydrate. So a typical macro distribution might be 30% protein, 60% fat, 10% carbs. Higher carb percentages are possible by focusing on very lean cuts of meat, but may negatively affect satiety in some people. Typically, the leaner one gets, the more one craves fat in the diet.

Won’t the Animal Protein Damage Your Kidneys?

No. Many studies show that protein intake even higher than 30% does not affect the kidneys.

What About Calories?

Good Question. I do track calories from time to time. I don’t think that there is any magical benefit on this diet when it comes to calories – if you eat more than you expend, you will gain weight, if you eat less, you’ll lose weight. But since it is impossible to accurately track intake and expenditure, I prefer not to care too much about those numbers. Ultimately it’s your body composition – measured by DEXA, impedance scale or waist circumference – which will show whether you are eating the proper amount of food.

Is This A Ketogenic Diet?

At its core the diet is ketogenic in nature, since meat contains virtually no carbohydrates. But the diet is also heavy in protein and technically the remaining 20% of calories could come from carbs (vegetables and fruit), which means that ketosis is not guaranteed on this diet – it is not the goal. Another way of putting it is that this diet does not rely on dietary carbohydrate to feed the brain or other cells which may require glucose – instead, it aims to optimize metabolic flexibility so that those needs can be met by using fat, ketones or gluconeogenesis.

So It’s a High-Fat Diet – Does That Mean Adding Butter And Oil To Every Meal?

No, not at all – in fact rather the opposite! Butter, oil and cream are mostly empty calories and should be used sparingly. I use butter (ghee, to be precise) when I cook steak, to get a better sear and because I like the taste. But on this diet I try to get the fat (which is necessary as an energy source) mainly from meat, cheese and fish. I find that much more satiating and rewarding, and it also makes the diet much less “greasy” and more tolerable for people who can’t stomach oils and fats.

Won’t (Red) Meat Increase Your Risk Of Cancer?

No. There is this persistent myth that meat causes cancer, but it is not supported by the best available scientific evidence. There are some studies which incriminate meat, but there are many others which exonerate it, and many of the incriminating studies can be shown to be seriously flawed. In my opinion, which is shared by more and more researchers, meat is not a problem – but sugar and industrial seed oils may be.

Won’t the Lack of Fiber Cause Colon Cancer?

No. Again, there is much discussion and misinformation in the media. A lot of flawed science exists which goes back to the beginning of the 20th century and people like Dennis Burkett or Harvey Kellogg, who were pushing a fiber-rich diet for various unscientific reasons. Fiber may actually be an anti-nutrient in many cases, causing problems like bloating, flatulence, IBS and aggravating serious conditions like Crohns Disease or diverticulitis.

But Don’t You Get Constipated On A Diet Low In Veggies And Fruit?

No. People on 100% meat diets commonly report no constipation. This makes sense, since meat is almost completely digested in the small intestine and doesn’t even make it to the colon. The human digestive system is very similar to that of dogs, which also thrive on a fiber free diet. As an interesting side note, dogs also tend to become diabetic if fed a diet higher in carbs and fiber (some dog foods contain potatoes and legumes).

My first hand experience, which is consistent with other meat-eaters, is that increasing veggies and fruit intake leads to bloating and having to go to the toilet more frequently and unpredictably/explosively, while removing them entirely leads to completely “regular”, but less frequent (a good thing) bowel movements. Ok, maybe that was a case of “too much information”, but frankly, it makes quite a difference in one’s every day life, so it is important to speak about.

But The Saturated Fat and Cholesterol Will Clog Your Arteries?

No. This myth is the most pervasive of all – the biggest scientific mistake in the field of modern nutritional science. Fortunately it is also the one which by now (2018) is mostly on its way out, with articles about the health benefits of high-fat dairy and animal products coming out on an almost weekly basis.

Shouldn’t We Eat As Little Salt As Possible Though?

No. 5-10 grams per day is perfectly fine, more if you’re doing a lot of sports in warm weather. Especially on a diet which is low in carbs, ensuring proper salt intake is important. Eat too little salt, and you won’t feel good in terms of mood and energy – on any diet.

What about Vitamins and Minerals?

Not a problem. Since the diet allows for vegetables and fruit and because, despite misinformation to the contrary, meat does contain a decent amount of minerals and vitamins, I typically get plenty of everything. Some minerals will be lower – for example, potassium or manganese. Feel free to use supplements (for example vitamin D), but there are people who thrive on a 100% meat diet which is technically deficient in some vitamins or minerals. The fact that people thrive anyway suggests that the vitamin/mineral requirements change when you are on a largely meat-based diet. It may even be the case that when you eat only meat, requirements change completely, but that is a highly speculative hypothesis.

Why Meat – Can’t You Get Everything From Plants?

The obvious nutrient not found in plants is vitamin B12. Other than that, there are a number of nutrients which are not officially listed as essential (because our body can make them from other nutrients) which are only available in animal based foods. Carnitine is one obvious example. Another big topic is bio-availability. Nutrients in plants often come along with anti-nutrients which block absorption, or the plants might only provide a precursor of the actual nutrient which then has to be converted in the human body, which may or may not work efficiently. Example: vitamin A (beta-carotene).

What About Ethical Concerns?

This is the main concerns that many vegans have. Some of them argue based on nutrition, but when push comes to shove, what motivates them most is avoiding the suffering of sentient animals. That is why I argue for eating mostly ruminant meat, eggs and dairy: Cows and chicken can be grown responsibly, with minimal suffering, and they are also the key to sustainable agriculture.

What About The Environment?

Sustainable agriculture is largely about protecting the topsoil. The only way to do this are perennial plants – like grass. Only they have roots deep enough to ensure that the soil stays healthy. Ruminant animals live in harmony with grass, chicken as well. Now, if you also take into account that much more land supporting pastures exists on our planet than the small amount which is suitable for the monocrops required to feed the world the vegan way, it becomes clear that a meat-based diet is completely sustainable. Or at least, every bit as much as the opposite.


How to Thrive as a Vegan

In my last post I talked about three basic approaches to nutrition: Eat only plants, eat only animals, eat both. Simple enough – but how to thrive on the extreme ends of the spectrum? In this post we will look at how to optimize health and longevity on the vegan, plant-based end.

TL;DR: Supplement with vitamin B12 and “eat the rainbow”: Make sure to include a variety of different plants in your meals every day to make sure you eat a lot of fiber, anti-oxidants, essential amino acids, vitamins and slow burning carbs and healthy fats. Does it work? Well, it did not for me. I found it too complicated, not optimal for my digestive system, and in my opinion the science is not settled – neither on the healthfulness of plant-based, nor on the harmfulness of animal-based food. But the diet might still work for you!

Enter Dr. Michael Greger

81rvgjuwqllThis is probably the most important author when it comes to the arguments for the healthfulness of a plant-based diet. Greger has built a huge website at replete with videos on various interesting topics, also to be found on YouTube along with lectures and interviews. His specialty is discussing studies on nutrition, and the level of detail is astonishing. It is his book “How Not To Die” which convinced me to give the whole food plant based (WFPB) approach a try. There are many other popular vegan authors, but Greger is highly respected among most of them and represents the best and most articulate view on how/why this approach is healthy, which is why I will only talk about his book for this introduction – more about the others in future posts.

The book is divided into two parts: The first lists most chronic diseases – cardiovascular disease, cancer, … – and then basically links them to animal foods through a plethora of studies. The second part discusses how to construct a healthy diet:

  • Minimize processed foods
    “processed” = something good removed / something bad added
  • Eat from a variety of plant “types” (the “daily dozen“) to maximize micro-nutrient intake

You can check out the daily dozen for yourself in more detail. The main insight aside from the well known “fruits, vegetables and whole grains” advice is that in order to optimize nutrition, you need to also eat legumes (beans/lentils/peas), nuts, berries, flax seeds, leafy greens, cruciferous greens … and the list goes on. Supplementing with vitamin B12 is also prescribed.

Did It Work For Me?

In short: No.

I spent many weeks eating almost completely within this framework last year, and I discovered many tasty vegan menus and snacks. I annoyed my family, girlfriend and colleagues with strange dishes and vegetables, all of a sudden eating guacamole or hummus, putting banana slices on whole-wheat bread, eating ten times more vegetables than the others, using almond butter instead of butter, plant milks and soy yogurt instead of dairy, and so forth. I really enjoyed eating those foods and still do so occasionally or partially today.

However, my digestive system was less pleased. Gas and bloating were big issues and ultimately one of two major reasons that over time I got less and less enthusiastic. WFPB advocates claim that this is a typical problem that eventually goes away once you adapt to eating more fiber, but for me that didn’t really turn out to be the case.

The other big reason for abandoning the WFPB was that even though authors like Greger offer a very convincing narrative about the dangers of animal foods and the super-powers of plant-based food, in my opinion the science is not settled at all. Sure, there are many studies that support this view, but there are also many other studies which show the opposite. Vegans will object to that vehemently, arguing that it either isn’t true, or that there are much fewer studies in favor of animal products, or that these are all funded by industry. But having spent a lot of time following these discussions, I do think that there is a lot less certainty about this issue than either side (vegan/carnivore) proclaims. I will discuss specific aspects in future posts.

Can It Work For You?

Absolutely. I don’t think that it’s optimal, and there may be some vegans on YouTube and elsewhere that greatly exaggerate the health benefits of WFPB, but some people clearly thrive on it. Reading How Not To Die certainly will teach you a lot about nutrients, and about what kind of scientific studies are done in the field of nutrition. Giving it a try might introduce you to many options that you hadn’t even considered before. Just keep in mind that the book has an agenda, and that – despite claims to the contrary – it is a biased interpretation of the available science.