- The carnivore diet involves eating only animal products, no plants, and mostly meat.
- People claim that following the carnivore diet will help you lose weight, protect against disease, reduce inflammation, and increase testosterone levels.
- Like any highly restrictive diet, the carnivore diet can help you lose weight, but it’s almost certainly unhealthy to follow long term.
What if I told you that by eating nothing but meat and other animal products—no fruits, vegetables, or plant foods of any kind—you could . . .
- Lose fat without counting calories
- Bulletproof yourself against and even cure diabetes
- Prevent blood sugar spikes and crashes
- Increase your testosterone levels, build more muscle, and improve your athletic performance
. . . BUT WAIT, THERE’S MORE!
You may also be able to resolve digestive problems like bloating, gas, and constipation and overcome depression, fatigue, joint pain, and other maladies.
Well, according to a growing number of self-styled health and diet gurus, that’s exactly what happens when you follow the “carnivore diet,” which involves eating only animal products (along with water and salt).
One of these people is Dr. Shawn Baker, a former orthopedic surgeon and powerlifter who’s a more vocal proponent of this style of eating.
Baker was on Joe Rogan’s podcast back in December 2017 to spread the gospel of flesh eating, and he said many interesting things, including the following:
- “We eat for two reasons. We eat to get energy and to build animal tissue . . . you and I are animals—we’re animal tissue. The most efficient way to do that is just to eat some, because your body has everything in the proportions that we need it.” (Link)
- “When they determined that smoking caused cancer, the epidemiology showed a 2,000 percent increase in the incidence of cancer . . . when they compare that to meat and cancer, they found an 18 percent increase.” (Link)
- “If we look back into history, there’s all kinds of accounts of people using meat as an athletic performance enhancer. Back in the original Greek olympics, those guys knew that if they ate a lot of meat, they’d perform better.” (Link)
Such statements may sound rather preposterous at first blush, but who knows?
Scientists used to believe that cocaine improved digestion, lobotomies alleviated mental illness, and drinking mercury cured constipation, so it’s not a huge stretch to at least question some of the current sacred cows of nutrition, like the importance of eating plant foods.
Baker batters his credibility, however, by saying stuff like this:
“A molecule of glucose and a molecule of vitamin C are almost identical, and so they compete for the same transporters.”
Here’s what a vitamin C molecule looks like:
And here’s what a glucose molecule looks like:
Why yes, Baker, I see your point. Those molecules do look “almost identical,” just in a “completely different” kind of way. It makes sense if you don’t think about it!
Then there’s the whole “compete for the same transporters” thing.
Scientists have known for decades that while vitamin C can enter cells using some of the same transporters (think “passageways”) as glucose, cells also have special transporters for vitamin C that don’t accept glucose.
And so what we have here is someone who doesn’t seem to understand basic chemistry or biology . . . and who had his medical license revoked in 2017 for “incompetence” . . . dispensing radical dietary advice to the unsuspecting masses.
It’s stuff like this that can change people’s lives. In the bad way.
All that doesn’t necessarily mean we should throw the carnivorous baby out with the bathwater, however.
If you poke around online and read people’s experiences with the carnivore diet, you’ll find some compelling success stories.
Men and women of all ages and circumstances are saying that it has cured their arthritis, stomach bloating, headaches, insomnia, anxiety, brain fog, depression, and alcohol and nicotine addictions, as well as helped them build muscle, lose fat, and look and feel healthier than ever before.
On the other hand, there are decades of research showing that eating fruits, vegetables, and whole grains is healthy, and some evidence that suggests eating high amounts of animal products increases the risk of disease and dysfunction.
Which position has the weight of the evidence on its side?
Well, the short answer is that while it’s possible to be healthy on the carnivore diet (at least for a while), there’s an overwhelming amount of scientific research showing that it’s far from optimal and that there are much better options.
And in this article, you’re going to get the whole story, including . . .
- What the carnivore diet is
- Why people follow it
- What the benefits and downsides are
- How safe it is
. . . and more.
Let’s get started.
Want to listen to more stuff like this? Check out my podcast!
The carnivore diet—also often referred to as the “zero carb diet” or “ketogenic paleo diet”—is more or less exactly what it sounds like:
You eat only animal products (along with water and salt).
That means no fruits, vegetables, garnishes, or plant-based spices, oils, or seasonings.
Dairy is technically allowed, but many carnivore dieters also give that up to keep their carbohydrate intake as low as possible and minimize the chances of gastrointestinal distress.
It’s not clear where or when this trend started, but some of the more well-known adherents include Charles Washington, who claims to have been following the diet for over 10 years, and Joe and Charlene Andersen, who claim to have been following the diet for nearly 20 years.
Find the Perfect Supplements for You in Just 60 Seconds
You don't need supplements to build muscle, lose fat, and get healthy. But the right ones can help. Take this quiz to learn which ones are best for you.Take the Quiz
The primary foods allowed on the carnivore diet are red meat, fish, fowl, and eggs.
Here’s a grocery list of sorts:
- Beef steak
- Pork and lamb chops
- Ground beef
- Whole eggs
- Deli meat
- Beef and chicken liver
- Bone marrow
Processed meats like bacon, sausage, and beef jerky are also allowed, and hardier carnivore dieters emphasize organ meats like liver, kidneys, and heart, which are more nutritious than more commonly eaten types of meat.
Some proponents of the diet also insist that all foods should be organic, grass-fed, or wild caught, although most don’t consider this mandatory.
Plant-based condiments like horseradish, mustard, ketchup, barbecue sauce, soy sauce, and salsa are off limits. The strictest devotees also avoid pepper.
There are two main reasons people follow the carnivore diet:
- To lose weight and get healthy
- To resolve symptoms they believe are caused by food intolerances or allergies
You can find many examples of people who’ve lost weight following the carnivore diet, but as you probably know, this is simply a function of energy balance and can be achieved with any type of diet.
In other words, the carnivore diet offers no special weight loss effects. Many people just unconsciously eat fewer calories when they can only eat meat, which makes it much easier to lose weight.
Even more common than weight loss boasts, however, are stories of people using the carnivore diet to mitigate or even eliminate negative symptoms they associate with food intolerances or allergies.
A food intolerance is an unofficial term for a consistently negative reaction to a certain food or food group.
For example, some people experience negative side effects, both physical and psychological, after eating wheat, dairy, or fermented foods, and many assume this means they have an intolerance to something in those foods, like gluten, lactose, or histamines (which are found in fermented foods).
You’ll also often hear followers of the carnivore diet talk about how plants contain “antinutrients,” like lectins, phytic acid, and gluten, that prevent animals from being able to digest them (thereby serving as “natural defense mechanisms” against consumption).
These compounds are indeed found in many plant foods, including soy, wheat, corn, oats, tomatoes, apples, cherries, potatoes, carrots, zucchini, and others.
Meat doesn’t contain any of these compounds, so by eating nothing but meat, people can easily avoid any foods and substances that may trigger unwanted reactions in their bodies.
This is reasonable. It’s basically the first step of an elimination diet, a scientifically validated way to determine which foods you can comfortably eat and which you can’t.
By first removing all the potentially problematic foods and then gradually reintroducing them into your diet one by one, you can isolate which foods you shouldn’t eat based on how your body responds to each “challenge” (reintroduction).
Where the carnivore diet jumps the shark, however, is that it never progresses beyond that first step of wholesale elimination.
Instead of using it as a path back to a nutritious, balanced diet—a means to an end—many people see it as a destination in and of itself.
More on that soon.
Champions of the carnivore diet say that it can do many things, including:
- Cause weight loss
- Improve cardiovascular health
- Reduce inflammation
- Increase testosterone levels
- Prevent nutrient deficiencies
Let’s give these claims a healthy dose of science and see what shakes out.
Here are a few of the most scientifically proven ways to spontaneously cause weight loss without tracking calories:
- Eat more protein
- Drink more water with meals
- Limit the variety of foods you eat
- Eat less oil and refined flour and sugar
- Eat higher-volume foods that require thorough chewing
And that’s a perfect summary of the carnivore diet.
First, it entails eating a lot of protein—200 to 300 grams per day for many people—and if you’ve ever done this, you know how effective it is for killing your appetite.
Furthermore, it’s not uncommon for people to eat two to four pounds of meat per day while following the carnivore diet. As meat is about 70 percent water, this results in an additional one to two quarts of water intake per day, and the fact that it’s consumed with food enhances its satiating effects.
The carnivore diet is also highly restrictive, which is an effective way to suppress appetite and reduce calorie intake. The fact that it removes all the highly processed foods most people tend to overeat—bread, candy, ice cream, pastries, pizza, and the like—makes it even more effective in this regard.
Finally, meat takes up more space in the stomach than most other foods and requires plenty of chewing, both of which increase satiety and suppress appetite.
Thus, it’s not surprising that people have lost boatloads of weight with the carnivore diet, especially in the first couple of weeks, when the body flushes water and glycogen in response to carbohydrate restriction.
In other words, there’s nothing inherently special about the carnivore diet as far as weight loss goes.
“But muh insulinz though!” I hear the rabid hordes of cannibals moaning. “It keeps the insulinz at bay!”
Ah, yes, insulin, the metabolic villain du jour, supposedly responsible for all manner of metabolic malfunction.
And as far as the carnivore diet goes, many people claim it’s superior to other forms of low-carb dieting because it keeps insulin levels as low as possible, which in turn speeds up weight loss.
And then there’s reality.
For one thing, protein-rich foods raise insulin levels as much as or more than carb-rich foods.
Some say that the insulin response to high-protein foods like whey and beef is slower (as if this were somehow better), but this is also wrong. High-protein foods cause a rapid spike in insulin followed by a rapid decline just like high-carb foods.
Even if following the carnivore diet did keep insulin levels lower than other forms of low-carb dieting, that wouldn’t guarantee fat loss.
So long as calories are equal, people lose fat equally well regardless of what happens with insulin levels or how their body responds to it. Hell, even putting overweight people on drugs to reduce insulin levels fails to cause fat loss.
So, the bottom line is that the carnivore diet can help you lose weight, but no better than any other type of diet that has you eat fewer calories than you burn over time.
To learn more about how insulin relates to fat loss, check this article out:
One of the main reasons various health organizations recommend we limit our meat intake is to reduce our risk of cardiovascular disease.
In case you’re not familiar with them, saturated fat is a type of dietary fat that’s solid at room temperature, and cholesterol is a pale, waxy compound that’s chemically similar to dietary fat, present in all cells of the body and used to make hormones, vitamin D, and chemicals that help you digest your food.
Several decades ago, it was believed that foods that contained cholesterol, like eggs and meat, increased the risk of heart disease. We now know it’s not that simple.
It would be premature to say that foods high in cholesterol play no role in heart disease, but most experts now agree that eating cholesterol-rich foods doesn’t increase your risk of heart disease by any significant degree.
On the other hand, many foods high in cholesterol also contain high amounts of saturated fat, which is more of a cause for concern.
The long-held belief that saturated fat increases the risk of heart disease has been challenged by recent research, which many people following the carnivore diet like to throw around as proof that they’re right and the establishment and naysayers are wrong.
These scientists maintain that there is a strong association between high intake of saturated fat and heart disease and that we should follow the generally accepted dietary guidelines for saturated fat intake (less than 10 percent of daily calories) until we know more.
To put that in perspective, let’s say you eat about 2,500 calories per day, putting your daily upper limit on saturated fat around 30 grams.
If you’re following a normal, balanced diet, it’s easy to stay beneath that threshold. To reach it, you’d have to eat five ounces of cheddar cheese, 20 strips of bacon, or three large fully loaded cheeseburgers every day.
If you’re following the carnivore diet, however, you can easily exceed your upper limit regularly.
For instance, here’s the nutritional breakdown of two pounds (908 grams) of ribeye steak, a fattier cut of beef that’s a staple among many carnivore dieters:
- 1,535 calories
- 182 grams of protein
- 10 grams of carbs
- 85 grams of fat
- 33 grams of saturated fat
As you can see, 20 percent of the total calories of ribeye come from saturated fat, and for some cuts of meat it’s even higher.
This is why saturated fat intake is often double the recommended amount among people following the carnivore diet.
In defense of this practice, the same people often point to primitive peoples who are known for consuming lots of meat and saturated fat and held up as paragons of health, like the Masai in Africa and the Inuit in Alaska, Canada, and Greenland.
Such claims don’t stand up to scientific scrutiny.
For instance, an early study conducted by scientists at Vanderbilt Medical School showed that the Masai tribe in Africa had few markers of heart disease based on blood cholesterol levels and simple tests of heart function.
The researchers weren’t able to accurately measure or record what these tribespeople ate but assumed that many of their calories came from whole milk rich in saturated fat, but not meat, which they ate just one to five times per month.
The same researchers conducted autopsies on the hearts of 50 Masai tribespeople over a decade later, though, and found that they had extensive atherosclerosis (hardening and thickening of the arteries) that was on par with what you’d find in people eating a Western diet.
As far as the Inuit go, research conducted by scientists at the National Institute of Public Health has found that they have rates of heart disease similar to or even higher than that of your average American.
What’s more, neither of these groups actually follows a true carnivore diet. The Masai eat plenty of carbohydrate, provided by cow’s milk, and anywhere from 8 to 54 percent of the average Inuit’s daily calories comes from carbs.
The bottom line is that there’s very little data on how the carnivore diet affects the risk of heart disease over time.
That said, we can giggle at some anecdotal evidence by returning to (no longer) Dr. Shawn Baker, who shared his blood test results in a recent podcast interview with Robb Wolf.
After following the carnivore diet for over a year:
- His total cholesterol was 205, putting him in the category of “medium risk” for heart disease according to most health agencies.
- His HDL (“good” cholesterol) was 44, which is also solidly in the “medium-risk” category and only 4 points above the high-risk category.
- His fasting glucose level—also a risk factor for heart disease—was 127. A healthy fasting blood glucose level is generally less than 100, and the American Diabetes Association considers anything over 126 to be a sign of diabetes.
- His total testosterone was 237, which is less than half of what’s considered normal for a man in his early 50s and low enough to medically classify him as “low testosterone.” Low testosterone is also a risk factor for heart disease and diabetes.
- His blood vitamin D level was 30, which is flirting with a deficiency depending on who you ask. Low vitamin D levels are also a risk factor for heart disease.
In other words, these results suck.
To justify them, Baker claimed that such things are typical among athletes like himself. While there is evidence that some athletes have higher fasting blood sugar than sedentary people, I don’t know of any who justify the high cholesterol and low HDL cholesterol, testosterone, and vitamin D.
Furthermore, Baker said that his low testosterone levels might be due to a healthy downregulation of production in response to an increase in cellular sensitivity to the hormone. In other words, because his body might (probably doesn’t) respond better to testosterone now, it might not have to produce as much.
Where’s the evidence for this? you ask. Who knows? Who cares? Check your scientific privilege, bigot!
Then, of course, there’s the inconvenient fact that copious evidence shows that eating fruits and vegetables reduces the risk of heart disease, and that avoiding these foods increases this risk.
For example, one recent study conducted by scientists at the University of Nis concluded the following:
Those in the upper tertile of fruit consumption (> 5 items/day) had 60% lower risk for coronary heart disease . . . when compared to those in the lowest tertile (<1 item/day). Consumption of vegetable >3 items/day was associated with 70% lower risk of coronary heart disease compared to subjects who did not consume vegetables.
Another study conducted by scientists at the Norwegian University of Science and Technology found a strong correlation between low fruit and vegetable consumption and heart disease, cancer, and overall risk of death.
The bottom line is that according to the best evidence and expert opinions currently available, the carnivore diet likely increases your risk of heart disease.
“Inflammation” is an ambiguous, catch-all term for many unwanted physical symptoms, and according to many followers of the carnivore diet, eating a pile of meat every day reduces it.
Technically speaking, inflammation is a prolonged activation of the body’s immune system, and it’s generally measured by looking at levels of various chemicals in the body such as C-reactive protein and cytokines.
As proof that the carnivore diet is ideal for fighting inflammation, people often point to a study conducted by scientists at Boston University on 55 obese men and women.
Researchers split everyone into two groups:
- Group one consumed a diet that provided 55 percent of calories from fat, 35 percent of calories from protein, and 10 percent of calories from carbs.
- Group two consumed a diet that provided 25 percent of calories from fat, 15 percent of calories from protein, and 60 percent of calories from carbs.
The diets were designed to allow both groups to lose 1 pound per week for 12 weeks, and the scientists measured their weight, body composition, and blood levels of C-reactive protein at the beginning and end of the study.
After 12 weeks, group one saw a 30 percent drop in their C-reactive protein levels, whereas group two only saw a 3 percent reduction.
The carnivore crowd has interpreted these results to mean that fewer carbs = less inflammation = better health, but there’s more to the study than meets the eye.
First of all, like many other studies that “prove” low-carb diets are better than higher-carb diets, the low-carb group also ate more than twice as much protein. Right off the bat, this makes it impossible to say whether the benefits were from reducing carb or increasing protein intake.
Second, there was very loose control of diet quality in the study, so it’s also quite possible that the group eating more carbs was also eating more refined flour and sugar, which may increase C-reactive protein levels.
Third, and rather strangely, the group following the high-carb diet fared better in some blood markers, such as a greater reduction in total and LDL cholesterol, and there’s no way for us to know which group ultimately would have experienced better health over the long term.
Another inflammation tidbit worth addressing is the claim that eating plants can trigger inflammation.
There is evidence that some people can have negative reactions to certain foods, including certain types of carbs (FODMAPs) like grains, beans, dairy, and even some fruit, and that people with autoimmune disease may benefit from avoiding gluten.
There’s very little evidence any of these reactions are caused by inflammation, however, or that eating only meat is the optimal solution.
The bottom line is that any claims about the carnivore diet reducing inflammation are based more on wishful thinking and willful misinterpretation than hard facts.
Find the Best Diet for You in Just 60 Seconds
How many calories should you eat? What about "macros?" What foods should you eat? Take our 60-second quiz to get science-based answers to these questions and more.Take the Quiz
People who follow the carnivore diet, and other high-fat diets, often claim that it can increase your testosterone levels.
And this, in turn, can lead to a number of benefits ranging from fat loss to muscle gain, increased libido, greater energy and endurance, and more.
There’s truth here.
Eating more dietary fat can indeed increase your testosterone levels, but not as significantly as many high-fat dieters would have you believe.
In other words, while a high-fat diet can bump up your testosterone production, it can’t help you lose fat or build muscle faster or turn you into an alpha male sex god.
To understand why, let’s start by reviewing a commonly cited study conducted by scientists at the National Cancer Institute.
The researchers split 43 men between the ages of 19 and 56 into two groups:
- Group one followed a diet that provided 41 percent of calories from fat with most of that fat coming from saturated sources.
- Group two followed a diet that provided 19 percent of calories from fat with most of that fat coming from polyunsaturated sources (polyunsaturated fats are liquid at room temperature, like canola oil).
Both groups ate the same number of calories, the same amount of protein, and more or less the same kinds of foods during the study, and all the meals were provided by the researchers to ensure compliance.
After 10 weeks, the researchers found that group one—which consumed twice as much fat as group two—had 13 percent higher total testosterone levels than group two.
Another study conducted by scientists at the National Public Health Institute of Finland showed similar results.
While a 13 percent increase in testosterone might sound good on paper, research clearly shows it’s not nearly enough to move the needle in terms of fat loss, muscle gain, or even general health and well-being.
For example, it’s well known that weightlifting can also temporarily boost testosterone levels postworkout by as much as 15 percent.
Does this lead to greater muscle gain and fat loss, though?
Scientists at McMaster University investigated this relationship in a study conducted with young, resistance-trained men who did five weightlifting workouts per week and followed a standard “bodybuilding” diet.
After 12 weeks, scientists found that exercise-induced spikes in anabolic hormones like testosterone, growth hormone, and IGF-1 had no effect on overall muscle growth or strength gains.
That is, the size of the hormonal responses seen in the subjects varied widely, but there was no significant difference in terms of muscle and strength gains.
Another study worth reviewing was conducted by scientists at Charles R. Drew University of Medicine and Science.
This one involved manipulating the testosterone levels of 61 young, healthy men using a combination of testosterone and drugs to inhibit natural testosterone production.
After 20 weeks, scientists found there was a dose-dependent relationship between testosterone and leg strength and power (higher testosterone levels meant more strength and power), but the effects weren’t significant until testosterone levels exceeded the top of the natural range by about 20 to 30 percent (about 1,200 ng/dL).
And just to lend further perspective on the matter, let’s review a bit of steroid research.
Scientists at Maastricht University published an extensive review of studies related to the use of anabolic steroids in 2004 and found the following:
- Muscle gains in people lifting weights on steroids ranged from 4.5 to 11 pounds over the short term (less than 10 weeks).
- The largest amount of muscle gain over the short term was 15.5 pounds over the course of 6 weeks. (In case you’re wondering why the large variation in gains, a multitude of factors ultimately determined the results, including training history, genetics, workout programming, diet, etc.)
Now, compare this to what you can achieve naturally and my point becomes clear:
Even when you blast your testosterone through the roof with anabolic steroids, it doesn’t necessarily mean you’re going to gain “shocking” amounts of muscle.
And if that’s the case with the sky-high testosterone levels that come with drug use, what does that tell us about small fluctuations that can occur within the physiological normal ranges?
It’s just not going to make much of a difference except in the most extreme cases of, let’s say, going from the absolute bottom of normal to the top.
This is one of the reasons why I recommend that you eat a high-protein, high-carb, and moderate-fat diet when you’re trying to build muscle.
It allows you to fully take advantage of the significant muscle-building benefits of both protein and carbs, as opposed to chasing negligible changes in hormones with extreme changes in diet.
The bottom line is that the carnivore diet isn’t going to skyrocket your testosterone levels, help you build more muscle, or improve your libido, energy, or mood.
You’ve likely heard that a healthy diet is a balanced one.
Different foods contain different levels of various vitamins and minerals, so by consuming many different foods and food groups, you can ensure you’re getting enough of everything your body needs.
Thus, one of the first things many people ask about the carnivore diet is: How do I get all the nutrition I need from steaks and hamburgers?
Well, meat is a highly nutritious food, but it’s also very low in several vital nutrients like vitamin C and fiber.
Vitamin C is important because it’s involved in many different functions in the body, including wound healing, immune function, iron absorption, and protecting cells from oxidative damage.
When you consume very little vitamin C (less than 10 mg per day) for long enough, you can develop scurvy, which causes inflammation of the gums and tooth loss, fatigue, skin sores, joint pain, and eventually death.
The carnivore diet provides very little of either, so how can it possibly be considered healthy?
Let’s tackle vitamin C first.
The recommended daily intake (RDI) of vitamin C for the average adult man is 90 mg and 75 mg for the average adult woman.
Most kinds of meat, including chicken, turkey, beef, lamb, and pork, contain little or no vitamin C. The one exception is organ meats, like liver, heart, and kidney, which contain trace amounts of vitamin C.
For example, beef liver contains 1 mg of vitamin C per 100 grams, lamb liver contains 4 mg, and chicken liver contains 18 mg. That means if you were to try to get all your daily vitamin C from only chicken liver, you’d need to eat over one pound per day (without throwing any of it up!).
For comparison’s sake, orange contains 53 mg of vitamin C per 100 grams, more than half of your daily requirement.
So, how are you supposed to get enough vitamin C without eating plants?
The standard carnivore-diet-approved response is that you don’t need much vitamin C to be healthy if you aren’t eating much carbohydrate.
In fact, this is exactly what Dr. Shawn Baker said in the 2017 interview with Joe Rogan I referenced earlier, and for two reasons.
First, remember the glucose and vitamin C transporter bit we reviewed?
Well, Baker’s argument was that because vitamin C and glucose compete for the same transporters (they don’t), and because a low-carb diet results in generally lower levels of insulin (it does), restricting carbohydrate intake reduces the need for vitamin C because your body can better absorb what it’s getting.
And as a corollary, that increasing carbohydrate intake increases the need for vitamin C.
That sounds sciency and stuff, but as I previously noted, it’s completely wrong. Vitamin C is able to enter cells through transporters that are unaffected by glucose (SVCT1 and SVCT2), and therefore, your body has no problem absorbing or using vitamin C regardless of your carbohydrate intake.
Baker, and others like him, also claimed that the RDI for vitamin C, manganese, and all other nutrients for that matter is based on research conducted on people who eat large amounts of carbohydrate, and thus doesn’t apply to people who don’t.
There’s no evidence to support that theory, of course.
As far as we know, eating less carbohydrate doesn’t fundamentally and dramatically alter the body’s nutritional requirements, and to assume otherwise is not only speculative but potentially dangerous.
And this is especially true with the carnivore diet, which is about as restrictive as you can possibly get.
Although there’s no research on how this style of eating plays out nutritionally, we can form an educated guess by reviewing a study conducted by scientists at the Department of Nutritional Research and Education, which analyzed the nutrient density of four popular weight loss diets: the Atkins Diet, the South Beach Diet, the Dash Diet, and the Best Life Diet.
The researchers added up the average calories and micronutrients provided by three days’ worth of meal plans for each diet and compared them to the RDI for each micronutrient.
They found that on average, the four diets provided sufficient amounts of just 12 of the 27 micronutrients they measured. They also estimated that you’d have to eat 27,575 calories per day on average to reach sufficiency for all 27 micronutrients.
I can only imagine how much meat, fish, and eggs you’d have to eat every day to achieve nutritional sufficiency.
“If what you’re saying is true,” a zealous carnivore might say, “why don’t we see a bunch of scurvy among my people?”
A good question with a simple answer: the body can go for months with a very low vitamin C intake before the wheels start to fall off, and as long as you consume at least about 10 mg of vitamin C per day, it’s unlikely you’ll develop serious problems. In one documented case, it took eight months without vitamin C to develop scurvy.
That doesn’t mean so little vitamin C is optimal, however, and it very well might have negative health consequences in the long run.
We also can’t discount the likelihood that people are secretly cheating on their carnivore diets. That is, despite claiming to only eat animal products, they might occasionally eat some fruits, vegetables, or meals that otherwise contain plant foods.
It wouldn’t take much plant food to make a big difference, either. For instance, assuming you get no vitamin C from animal products you eat, eating just two oranges per week would be enough to prevent scurvy in most people.
So, when you consider the fact that humans don’t need much vitamin C to avoid scurvy, the small amount of vitamin C provided by animal foods, and the possibility of an orange or two (or other vitamin C–rich foods like broccoli, peppers, and strawberries) here and there, it’s not surprising people are able to follow the carnivore diet for long periods of time without falling apart.
“Not dying of a third-world disease” shouldn’t be the goal of our diet and lifestyle, though. Living a long, healthy, vital life—thriving rather than just surviving—should be.
The story is similar for fiber.
Humans don’t need fiber to survive, so you could theoretically go the rest of your life without ever eating another gram of it.
There are mountains of evidence, though, that your life is probably going to be shorter and more painful if you eliminate fiber from it.
For example, studies conducted by scientists at the Institute of Social and Preventive Medicine, Imperial College, the University of Minnesota, Harvard University, and Tufts University, as well as many others from universities all around the world, have shown that eating more fiber helps reduce the risk of cancer, heart disease, metabolic syndrome, type 2 diabetes, and diverticulitis, to name a few.
The bottom line is that yes, you can follow the carnivore diet without developing a true, life-threatening nutritional deficiency, but chances are good you’d live a longer, healthier life if you ate plants, too.
Some Nutritionists Charge Hundreds of Dollars for This Diet "Hack" . . .
. . . and it's yours for free. Take our 60-second quiz and learn exactly how many calories you should eat, what your "macros" should be, what foods are best for you, and more.Take the Quiz
The carnivore diet involves eating nothing but animal products (mostly meat), water, and salt.
As you can guess, this hyperrestrictive approach can help people lose weight (by naturally reducing calorie intake) and can make for a good first step in an elimination diet, but that’s where the benefits end.
- It likely increases the risk of heart disease.
- There’s very little evidence that it reduces inflammation and associated disease or dysfunction.
- Eating more fat, as you would on a carnivore diet, will likely raise your testosterone levels, but not enough to have any significant impact on muscle gain, fat loss, libido, or anything else.
- By only eating animal products, you’ll also be consuming significantly less than the RDI for vitamin C and fiber, which greatly increases the risk of many different diseases.
So, in the final analysis, the carnivore diet is just a more extreme version of every other low-carb diet out there.
As with most fad diets, it burst onto the scene through major media personalities and attention, not scientific research or validation. And now it gets to run its course and capture its share of attention and dollars.
What you need to know, though, is unless you have serious digestive issues and need to follow an elimination diet, the carnivore diet has nothing to offer you.
If all you want to do is lose fat, build muscle, get healthy, and actually enjoy your diet, let me introduce you to something better.
It’s called flexible dieting, and you can learn more about it here:
What’s your take on the carnivore diet? Have anything else to share? Let me know in the comments below!
+ Scientific References
- Hartgens, F., & Kuipers, H. (2004). Effects of androgenic-anabolic steroids in athletes. In Sports Medicine (Vol. 34, Issue 8, pp. 513–554). Sports Med. https://doi.org/10.2165/00007256-200434080-00003
- Kosova, E. C., Auinger, P., & Bremer, A. A. (2013). The Relationships between Sugar-Sweetened Beverage Intake and Cardiometabolic Markers in Young Children. Journal of the Academy of Nutrition and Dietetics, 113(2), 219–227. https://doi.org/10.1016/j.jand.2012.10.020
- Biesiekierski, J. R., Peters, S. L., Newnham, E. D., Rosella, O., Muir, J. G., & Gibson, P. R. (2013). No effects of gluten in patients with self-reported non-celiac gluten sensitivity after dietary reduction of fermentable, poorly absorbed, short-chain carbohydrates. Gastroenterology, 145(2). https://doi.org/10.1053/j.gastro.2013.04.051
- Krysiak, R., Szkróbka, W., & Okopień, B. (2019). The Effect of Gluten-Free Diet on Thyroid Autoimmunity in Drug-Naïve Women with Hashimoto’s Thyroiditis: A Pilot Study. Experimental and Clinical Endocrinology and Diabetes, 127(7), 417–422. https://doi.org/10.1055/a-0653-7108
- Dorgan, J. F., Judd, J. T., Longcope, C., Brown, C., Schatzkin, A., Clevidence, B. A., Campbell, W. S., Nair, P. P., Franz, C., Kahle, L., & Taylor, P. R. (1996). Effects of dietary fat and fiber on plasma and urine androgens and estrogens in men: A controlled feeding study. American Journal of Clinical Nutrition, 64(6), 850–855. https://doi.org/10.1093/ajcn/64.6.850
- Hämäläinen, E., Adlercreutz, H., Puska, P., & Pietinen, P. (1984). Diet and serum sex hormones in healthy men. Journal of Steroid Biochemistry, 20(1), 459–464. https://doi.org/10.1016/0022-4731(84)90254-1
- Kvorning, T., Andersen, M., Brixen, K., Schjerling, P., Suetta, C., & Madsen, K. (2007). Suppression of testosterone does not blunt mRNA expression of myoD, myogenin, IGF, myostatin or androgen receptor post strength training in humans. Journal of Physiology, 578(2), 579–593. https://doi.org/10.1113/jphysiol.2006.122671
- West, D. W. D., & Phillips, S. M. (2012). Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training. European Journal of Applied Physiology, 112(7), 2693–2702. https://doi.org/10.1007/s00421-011-2246-z
- Storer, T. W., Magliano, L., Woodhouse, L., Lee, M. L., Dzekov, C., Dzekov, J., Casaburi, R., & Bhasin, S. (2003). Testosterone dose-dependently increases maximal voluntary strength and leg power, but does not affect fatigability or specific tension. Journal of Clinical Endocrinology and Metabolism, 88(4), 1478–1485. https://doi.org/10.1210/jc.2002-021231
- Adam-Perrot, A., Clifton, P., & Brouns, F. (2006). Low-carbohydrate diets: Nutritional and physiological aspects. In Obesity Reviews (Vol. 7, Issue 1, pp. 49–58). Obes Rev. https://doi.org/10.1111/j.1467-789X.2006.00222.x
- Hodges, R. E., Baker, E. M., Hood, J., Sauberlich, H. E., & March, S. C. (1969). Experimental scurvy in man. The American Journal of Clinical Nutrition, 22(5), 535–548. https://doi.org/10.1093/ajcn/22.5.535
- Calton, J. B. (2010). Prevalence of micronutrient deficiency in popular diet plans. Journal of the International Society of Sports Nutrition, 7, 24. https://doi.org/10.1186/1550-2783-7-24
- Herbert, V. (1981). ‘Scalded Sardine’ Scurvy. In JAMA: The Journal of the American Medical Association (Vol. 246, Issue 19, pp. 2155–2156). JAMA. https://doi.org/10.1001/jama.1981.03320190015011
- Padayatty, S. J., & Levine, M. (2001). New insights into the physiology and pharmacology of vitamin C. In CMAJ (Vol. 164, Issue 3, pp. 353–355). Canadian Medical Association. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC80729/
- Alhassan, S., Kim, S., Bersamin, A., King, A. C., & Gardner, C. D. (2008). Dietary adherence and weight loss success among overweight women: Results from the A to Z weight loss study. International Journal of Obesity, 32(6), 985–991. https://doi.org/10.1038/ijo.2008.8
- Smith, C. F., Williamson, D. A., Bray, G. A., & Ryan, D. H. (1999). Flexible vs. rigid dieting strategies: Relationship with adverse behavioral outcomes. Appetite, 32(3), 295–305. https://doi.org/10.1006/appe.1998.0204
- Levi, F., Pasche, C., Lucchini, F., Chatenoud, L., Jacobs, D. R., & La Vecchia, C. (2000). Refined and whole grain cereals and the risk of oral, oesophageal and laryngeal cancer. European Journal of Clinical Nutrition, 54(6), 487–489. https://doi.org/10.1038/sj.ejcn.1601043
- Aune, D., Chan, D. S. M., Greenwood, D. C., Vieira, A. R., Navarro Rosenblatt, D. A., Vieira, R., & Norat, T. (2012). Dietary fiber and breast cancer risk: A systematic review and meta-analysis of prospective studies. In Annals of Oncology (Vol. 23, Issue 6, pp. 1394–1402). Ann Oncol. https://doi.org/10.1093/annonc/mdr589
- Pereira, M. A., O’Reilly, E., Augustsson, K., Fraser, G. E., Goldbourt, U., Heitmann, B. L., Hallmans, G., Knekt, P., Liu, S., Pietinen, P., Spiegelman, D., Stevens, J., Virtamo, J., Willett, W. C., & Ascherio, A. (2004). Dietary Fiber and Risk of Coronary Heart Disease: A Pooled Analysis of Cohort Studies. Archives of Internal Medicine, 164(4), 370–376. https://doi.org/10.1001/archinte.164.4.370
- Rimm, E. B. (1996). Vegetable, Fruit, and Cereal Fiber Intake and Risk of Coronary Heart Disease Among Men. JAMA: The Journal of the American Medical Association, 275(6), 447. https://doi.org/10.1001/jama.1996.03530300031036
- McKeown, N. M., Meigs, J. B., Liu, S., Saltzman, E., Wilson, P. W. F., & Jacques, P. F. (2004). Carbohydrate Nutrition, Insulin Resistance, and the Prevalence of the Metabolic Syndrome in the Framingham Offspring Cohort. Diabetes Care, 27(2), 538–546. https://doi.org/10.2337/diacare.27.2.538
- Ruth, M. R., Port, A. M., Shah, M., Bourland, A. C., Istfan, N. W., Nelson, K. P., Gokce, N., & Apovian, C. M. (2013). Consuming a hypocaloric high fat low carbohydrate diet for 12 weeks lowers C-reactive protein, and raises serum adiponectin and high density lipoprotein-cholesterol in obese subjects. Metabolism: Clinical and Experimental, 62(12), 1779–1787. https://doi.org/10.1016/j.metabol.2013.07.006
- MANN, G. V., SHAFFER, R. D., ANDERSON, R. S., & SANDSTEAD, H. H. (1964). CARDIOVASCULAR DISEASE IN THE MASAI. Journal of Atherosclerosis Research, 4(4), 289–312. https://doi.org/10.1016/S0368-1319(64)80041-7
- MANN, G. V., SPOERRY, A., GARY, M., & JARASHOW, D. (1972). ATHEROSCLEROSIS IN THE MASAI1. American Journal of Epidemiology, 95(1), 26–37. https://doi.org/10.1093/oxfordjournals.aje.a121365
- Nestel, P. (1986). A society in transition: Developmental and seasonal influences on the nutrition of Maasai women and children. https://cgspace.cgiar.org/handle/10568/50112
- Bjerregaard, P., Young, T. K., & Hegele, R. A. (2003). Low incidence of cardiovascular disease among the Inuit - What is the evidence? Atherosclerosis, 166(2), 351–357. https://doi.org/10.1016/S0021-9150(02)00364-7
- Bang, H. O., Dyerberg, J., & Hjørne, N. (1976). The Composition of Food Consumed by Greenland Eskimos. Acta Medica Scandinavica, 200(1–6), 69–73. https://doi.org/10.1111/j.0954-6820.1976.tb08198.x
- Park, C., Guallar, E., Linton, J. A., Lee, D. C., Jang, Y., Son, D. K., Han, E. J., Baek, S. J., Yun, Y. D., Jee, S. H., & Samet, J. M. (2013). Fasting glucose level and the risk of incident atherosclerotic cardiovascular diseases. Diabetes Care, 36(7), 1988–1993. https://doi.org/10.2337/dc12-1577
- Kelsey, T. W., Li, L. Q., Mitchell, R. T., Whelan, A., Anderson, R. A., & Wallace, W. H. B. (2014). A validated age-related normative model for male total testosterone shows increasing variance but no decline after age 40 years. PLoS ONE, 9(10). https://doi.org/10.1371/journal.pone.0109346
- Kumar, P., Kumar, N., Thakur, D. S., & Patidar, A. (2010). Male hypogonadism: Symptoms and treatment. In Journal of Advanced Pharmaceutical Technology and Research (Vol. 1, Issue 3, pp. 297–301). Wolters Kluwer -- Medknow Publications. https://doi.org/10.4103/0110-5558.72420
- Goodale, T., Sadhu, A., Petak, S., & Robbins, R. (2017). Testosterone and the Heart. In Methodist DeBakey cardiovascular journal (Vol. 13, Issue 2, pp. 68–72). Methodist DeBakey Heart & Vascular Center. https://doi.org/10.14797/mdcj-13-2-68
- Al Hayek, A., Ajlouni, K., Khader, Y., Jafal, S., Khawaja, N., & Robert, A. (2013). Prevalence of low testosterone levels in men with type 2 diabetes mellitus: a cross-sectional study. Journal of Family and Community Medicine, 20(3), 179. https://doi.org/10.4103/2230-8229.122006
- Manson, J. A. E., Brannon, P. M., Rosen, C. J., & Taylor, C. L. (2016). Vitamin D Deficiency - Is There Really a Pandemic? In New England Journal of Medicine (Vol. 375, Issue 19, pp. 1817–1820). Massachussetts Medical Society. https://doi.org/10.1056/NEJMp1608005
- Judd, S. E., & Tangpricha, V. (2009). Vitamin D deficiency and risk for cardiovascular disease. American Journal of the Medical Sciences, 338(1), 40–44. https://doi.org/10.1097/MAJ.0b013e3181aaee91
- Thomas, F., Pretty, C. G., Desaive, T., & Chase, J. G. (2016). Blood Glucose Levels of Subelite Athletes during 6 Days of Free Living. Journal of Diabetes Science and Technology, 10(6), 1335–1343. https://doi.org/10.1177/1932296816648344
- He, F. J., Nowson, C. A., Lucas, M., & MacGregor, G. A. (2007). Increased consumption of fruit and vegetables is related to a reduced risk of coronary heart disease: Meta-analysis of cohort studies. Journal of Human Hypertension, 21(9), 717–728. https://doi.org/10.1038/sj.jhh.1002212
- Aune, D., Giovannucci, E., Boffetta, P., Fadnes, L. T., Keum, N. N., Norat, T., Greenwood, D. C., Riboli, E., Vatten, L. J., & Tonstad, S. (2017). Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality-A systematic review and dose-response meta-analysis of prospective studies. International Journal of Epidemiology, 46(3), 1029–1056. https://doi.org/10.1093/ije/dyw319
- Hartley, L., Igbinedion, E., Holmes, J., Flowers, N., Thorogood, M., Clarke, A., Stranges, S., Hooper, L., & Rees, K. (2013). Increased consumption of fruit and vegetables for the primary prevention of cardiovascular diseases. Cochrane Database of Systematic Reviews, 2013(6). https://doi.org/10.1002/14651858.CD009874.pub2
- Bazzano, L. A., Serdula, M. K., & Liu, S. (2003). Dietary intake of fruits and vegetables and risk of cardiovascular disease. In Current Atherosclerosis Reports (Vol. 5, Issue 6, pp. 492–499). Current Science Ltd. https://doi.org/10.1007/s11883-003-0040-z
- Miquel-Kergoat, S., Azais-Braesco, V., Burton-Freeman, B., & Hetherington, M. M. (2015). Effects of chewing on appetite, food intake and gut hormones: A systematic review and meta-analysis. In Physiology and Behavior (Vol. 151, pp. 88–96). Elsevier Inc. https://doi.org/10.1016/j.physbeh.2015.07.017
- Kreitzman, S. N., Coxon, A. Y., & Szaz, K. F. (1992). Glycogen storage: Illusions of easy weight loss, excessive weight regain, and distortions in estimates of body composition. American Journal of Clinical Nutrition, 56(1 SUPPL.). https://doi.org/10.1093/ajcn/56.1.292S
- Bogardus, C., LaGrange, B. M., Horton, E. S., & Sims, E. A. H. (1981). Comparison of carbohydrate-containing and carbohydrate-restricted hypocaloric diets in the treatment of obesity. Endurance and metabolic fuel homeostasis during strenuous exercise. Journal of Clinical Investigation, 68(2), 399–404. https://doi.org/10.1172/JCI110268
- Phinney, S. D., Horton, E. S., Sims, E. A. H., Hanson, J. S., Danforth, E., & Lagrange, B. M. (n.d.). Capacity for Moderate Exercise in Obese Subjects after Adaptation to a Hypocaloric, Ketogenic Diet.
- Naude, C. E., Schoonees, A., Senekal, M., Young, T., Garner, P., & Volmink, J. (2014). Low carbohydrate versus isoenergetic balanced diets for reducing weight and cardiovascular risk: A systematic review and meta-analysis. In PLoS ONE (Vol. 9, Issue 7). Public Library of Science. https://doi.org/10.1371/journal.pone.0100652
- Johnston, C. S., Tjonn, S. L., Swan, P. D., White, A., Hutchins, H., & Sears, B. (2006). Ketogenic low-carbohydrate diets have no metabolic advantage over nonketogenic low-carbohydrate diets. American Journal of Clinical Nutrition, 83(5), 1055–1061. https://doi.org/10.1093/ajcn/83.5.1055
- Pal, S., & Ellis, V. (2010). The acute effects of four protein meals on insulin, glucose, appetite and energy intake in lean men. British Journal of Nutrition, 104(8), 1241–1248. https://doi.org/10.1017/S0007114510001911
- Salehi, A., Gunnerud, U., Muhammed, S. J., Stman, E., Holst, J. J., Björck, I., & Rorsman, P. (2012). The insulinogenic effect of whey protein is partially mediated by a direct effect of amino acids and GIP on β-cells. Nutrition and Metabolism, 9(1). https://doi.org/10.1186/1743-7075-9-48
- Holt, S. H. A., Brand Miller, J. C., & Petocz, P. (1997). An insulin index of foods: The insulin demand generated by 1000-kJ portions of common foods. American Journal of Clinical Nutrition, 66(5), 1264–1276. https://doi.org/10.1093/ajcn/66.5.1264
- Gardner, C. D., Trepanowski, J. F., Gobbo, L. C. D., Hauser, M. E., Rigdon, J., Ioannidis, J. P. A., Desai, M., & King, A. C. (2018). Effect of low-fat VS low-carbohydrate diet on 12-month weight loss in overweight adults and the association with genotype pattern or insulin secretion the DIETFITS randomized clinical trial. JAMA - Journal of the American Medical Association, 319(7), 667–679. https://doi.org/10.1001/jama.2018.0245
- Due, A., Flint, A., Eriksen, G., Møller, B., Raben, A., Hansen, J. B., & Astrup, A. (2007). No effect of inhibition of insulin secretion by diazoxide on weight loss in hyperinsulinaemic obese subjects during an 8-week weight-loss diet. Diabetes, Obesity and Metabolism, 9(4), 566–574. https://doi.org/10.1111/j.1463-1326.2006.00645.x
- Zazpe, I., Beunza, J. J., Bes-Rastrollo, M., Warnberg, J., De La Fuente-Arrillaga, C., Benito, S., Vázquez, Z., & Martínez-González, M. A. (2011). Egg consumption and risk of cardiovascular disease in the SUN Project. European Journal of Clinical Nutrition, 65(6), 676–682. https://doi.org/10.1038/ejcn.2011.30
- Micha, R., Wallace, S. K., & Mozaffarian, D. (2010). Red and processed meat consumption and risk of incident coronary heart disease, stroke, and diabetes mellitus: A systematic review and meta-analysis. Circulation, 121(21), 2271–2283. https://doi.org/10.1161/CIRCULATIONAHA.109.924977
- Berger, S., Raman, G., Vishwanathan, R., Jacques, P. F., & Johnson, E. J. (2015). Dietary cholesterol and cardiovascular disease: a systematic review and meta-analysis. The American Journal of Clinical Nutrition, 102(2), 276–294. https://doi.org/10.3945/ajcn.114.100305
- Siri-Tarino, P. W., Sun, Q., Hu, F. B., & Krauss, R. M. (2010). Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. American Journal of Clinical Nutrition, 91(3), 535–546. https://doi.org/10.3945/ajcn.2009.27725
- Pedersen, J. I., James, P. T., Brouwer, I. A., Clarke, R., Elmadfa, I., Katan, M. B., Kris-Etherton, P. M., Kromhout, D., Margetts, B. M., Mensink, R. P., Norum, K. R., Rayner, M., & Uusitupa, M. (2011). The importance of reducing SFA to limit CHD. In British Journal of Nutrition (Vol. 106, Issue 7, pp. 961–963). Cambridge University Press. https://doi.org/10.1017/S000711451100506X
- Kromhout, D., Geleijnse, J. M., Menotti, A., & Jacobs, D. R. (2011). The confusion about dietary fatty acids recommendations for CHD prevention. In British Journal of Nutrition (Vol. 106, Issue 5, pp. 627–632). Cambridge University Press. https://doi.org/10.1017/S0007114511002236
- Willett, W. C. (2012). Dietary fats and coronary heart disease. In Journal of Internal Medicine (Vol. 272, Issue 1, pp. 13–24). J Intern Med. https://doi.org/10.1111/j.1365-2796.2012.02553.x
- Piepoli, M. F., Hoes, A. W., Agewall, S., Albus, C., Brotons, C., Catapano, A. L., Cooney, M. T., Corrà, U., Cosyns, B., Deaton, C., Graham, I., Hall, M. S., Hobbs, F. D. R., Løchen, M. L., Löllgen, H., Marques-Vidal, P., Perk, J., Prescott, E., Redon, J., … Gale, C. (2016). 2016 European Guidelines on cardiovascular disease prevention in clinical practice. In European Heart Journal (Vol. 37, Issue 29, pp. 2315–2381). Oxford University Press. https://doi.org/10.1093/eurheartj/ehw106
- Liang, W. J., Johnson, D., & Jarvis, S. M. (2001). Vitamin C transport systems of mammalian cells. Molecular Membrane Biology, 18(1), 87–95. https://doi.org/10.1080/09687680110033774
- Genkinger, J. M., & Koushik, A. (2007). Meat consumption and cancer risk. PLoS Medicine, 4(12), 1883–1886. https://doi.org/10.1371/journal.pmed.0040345
- Egger, J., Wilson, J., Carter, C. M., Turner, M. W., & Soothill, J. F. (1983). Effects of chronic β-blocker treatment on catecholamine levels in spontaneously hypertensive rats. Biochemical Pharmacology, 32(18), 2739–2743. https://doi.org/10.1016/S0140-6736(83)90866-8
- Daniels, M. C., & Popkin, B. M. (2010). Impact of water intake on energy intake and weight status: A systematic review. In Nutrition Reviews (Vol. 68, Issue 9, pp. 505–521). NIH Public Access. https://doi.org/10.1111/j.1753-4887.2010.00311.x
- Research, I. of M. (US) C. on M. N., & Marriott, B. M. (1995). Effects of Food Quality, Quantity, and Variety on Intake. https://www.ncbi.nlm.nih.gov/books/NBK232454/
- Chambers, L., McCrickerd, K., & Yeomans, M. R. (2015). Optimising foods for satiety. In Trends in Food Science and Technology (Vol. 41, Issue 2, pp. 149–160). Elsevier Ltd. https://doi.org/10.1016/j.tifs.2014.10.007
- Rolls, B. J., Castellanos, V. H., Halford, J. C., Kilara, A., Panyam, D., Pelkman, C. L., Smith, G. P., & Thorwart, M. L. (1998). Volume of food consumed affects satiety in men. American Journal of Clinical Nutrition, 67(6), 1170–1177. https://doi.org/10.1093/ajcn/67.6.1170