The "Carnivore Diet" is a plan that centers around eating meat and eggs (and not much else). While elimination diets can be effective, this is an extreme diet that is generally not recommended by dietitians because it restricts your body of many essential vitamins and nutrients, and it presents many potential health risks.
In the 20 years that I’ve been a dietitian, I’ve seen a lot of random diets come and go (and far too many overstay their welcome). As you’d expect, there have always been fringe weight-loss plans (tapeworms, anyone?), but few diets in history hold a candle to the most recent fringe diet darling: "The Carnivore Diet."
Basically, this fad -- and yes, it’s a fad -- is eating meat and eggs only. No vegetables, fruit, or any starches or sugars. Dairy products are allowed, but most carnivore dieters don't eat them due to their lactose, which is a sugar. Plant foods are considered "harmful" because of their alleged "anti-nutrients" (more on this in a moment).
The Carnivore Diet isn’t the same as the keto diet. In order to since to maintain ketosis, the keto diet consists of 80 percent fat. The Carnivore Diet is just meat.
A day's worth of food for a carnivore might be eggs and steak for breakfast, 2 steaks for lunch, and 2 steaks for dinner. In this world, avocados are not accepted (even though they're filled with "healthy fats) because they're a plant.
Held up against other ways of eating, I can’t see the carnivore diet having any redeeming qualities. Sure, you might lose weight, but that's only because you’re eating less ultra-processed food or less food overall (eating fewer calories will lead to weight loss).
The claims of The Carnivore Diet extend beyond weight loss. Many who follow the diet suggest that it has healed their arthritis, gastrointestinal issues, or other conditions. If you have a condition that appears to have resolved after starting this diet, it's an oversimplification of how your body works to assume that it's the actual diet that's causing the change.
For instance, symptoms could change because of gut bacteria dieoff, weight loss, the elimination of pretty much every single food besides meat, or even the placebo effect.
Some also say that the diet cures depression -- a claim that is both irresponsible and dangerous, as it may cause people to go off their required medications.
While this diet may be lower in calories than your normal way of eating, it’s based on a lot of untruths, n=1 anecdotes, and bad (or non-existent) science. The emotional effects of eating this diet can’t be ignored, either.
To help you understand why I'm against this eating approach, here are some of the biggest flaws and myths surrounding the Carnivore Diet.
Hello, Nutrient Deficiency
One of the biggest myths about the Carnivore Diet is that you can receive all of your essential vitamins and minerals from the meat that's available at most grocery stores.
While meat does contain a lot of nutrition, a meat-only diet also has several fundamental gaps that can lead to health problems. At a minimum, your diet would be can be low in vitamin C, unless you’re eating raw liver or eggs. Also, you wouldn't be eating any antioxidants (which are not present in meat), and you be missing out on fiber (which is an essential nutrient).
Fiber isn’t just for keeping you regular. It also feeds your good gut bacteria, which may affect everything from your mood to your immunity and weight. A Carnivore Diet could kill the bacteria in your gut (good and bad), which is perhaps why some people find relief from their gastrointestinal symptoms. Eventually, though, killing the good bacteria die will eventually become an issue.
Just because you can exist on a diet doesn’t mean that it’s a healthy choice. Do you want to just exist, or do you want to enjoy your life and be able to relax about eating? It's an important differentiation and a reason why the Carnivore Diet carries a lot of hidden risks.
Twisting Cultural Anthropology
Supporters of the Carnivore Diet love to point to the Inuit and Masaai as cultures that only ate meat and were still healthy and strong.
It’s important to note that studies done on Inuit and Masaai populations in terms of health were notoriously poor because the evidence was exceedingly difficult to obtain.
But, for the sake of the argument, let’s assume that people in these cultures had a longer lifespan and were generally healthy.
If you review their diets, the traditional Inuit ate a marine diet that was low in carbohydrates, such as starches, fruits, and vegetables. But, that doesn't mean they were following a carnivore diet as it's practiced today. Those cultures were not eating ribeye steaks fried in butter. Their diet was built on seal meat, walrus, and whale blubber, which are all high in vitamins A, E, D, and selenium. Whale skin and muktuk, which is a combination of whale skin mixed with blubber, contributed vitamin C to the diet.
The Inuit also ate plenty of organ meats and, ounce for ounce, their diets were higher in monounsaturated fats (not saturated fat). They were also more active than most of us.
The Masaai were active too; as a pastoral population, they walked everywhere. Their traditional diet consisted mostly of milk, meat, and blood, but was supplemented with tubers and plants, as well as honey.
A 2012 study in PLOS One suggests that the Masaai’s low incidence of cardiovascular disease, despite a diet phenomenally high in cholesterol, was most likely due to genetic mutations that allowed them to eat this way without increasing risk of disease.
Comparing different cultures is always a slippery slope because health doesn't occur in isolation. It's likely that most people in North America do not share the same genetic traits, activity levels, and diets of the Inuit or Masaai, so comparing them -- or any other population’s diet -- to Carnivore doesn’t make a whole lot of sense.
The Vegan Straw Man
All diets that are based on "one-source" of food are not created equal. Many who follow a meat-only plan suggest that the dietary approach is no different than a vegan or vegetarian lifestyle.
While the vegan diet consists of only plants, when it’s done correctly, this style of eating has a combination of carbohydrates, protein, and fats from a variety of plant-based foods.
The fiber and antioxidants that are present in plants (and not meat) have repeatedly been proven by credible research to be associated with a reduced risk of disease and contribute positively to overall health. Meat heavy diets have never shown any of those particular benefits.
The Toxic Carb Myth
Let's just tackle this head-on: there is absolutely nothing ‘toxic’ about carbohydrates or "anti-nutrients" in plants.
Avoiding lectins is the newest fearmongering diet approach. Lectins are a type of protein that are found in nightshades, legumes, and some vegetables. In some cases, such as in raw kidney beans, they can make you really sick. Fortunately, the lectins in beans are mostly denatured with cooking, which means you're not at risk. Even more importantly: when was the last time you ate raw beans and lentils? Because that's when you're really in danger.
The lectins in other plants have never been found to affect most of the population. Some people may be sensitive to them, but a blanket approach of "lectins are toxic for everyone" is wrong, reckless, and not a good reason to stop eating plants.
The only reason to limit carbs is if you're consuming foods that are too high in sugar and ultra-processed. This doesn’t mean you have to cut all carbs out of your life; there is still merit in eating whole grains - even in reduced amounts - for energy, fiber, and antioxidants.
The Saturated Fat Risk
Although saturated fat may not be as harmful to us as we previously thought, eating too much saturated fat can still increase your risk of heart disease if the saturated fat replaces mono or polyunsaturated fats in your diet.
While I don’t recommend cutting saturated fats from your diet, I advise people to choose a variety of all fats (except for trans fats), instead of concentrating on just one.
The Psychological Risk
As much as a meat-only diet isn't physically healthy, the psychological impact is equally dangerous. Limiting your diet to one or two foods and seeing food as fuel isn’t healthy. Food, as we know, is for so much more. This type of dietary approach can result in disordered eating behavior and a grossly distorted attitude towards foods that have never been proven to be harmful (like plants). In general, any diet that teaches you to fear food is a diet you should avoid.
How to Assess Diets
My advice: critically review any eating plan before you begin to follow it. A few simple questions can help you identify questionable plans. Who is giving the information? Are they claiming that their diet cures previously incurable diseases and conditions? Do you have to cut out healthy foods to be on this plan?
Eating doesn’t have to be a choice between an ultra-processed, carb-heavy diet or only meat. You can eat a balanced diet without going to either end of the spectrum, and you’ll likely be healthier for it.