The Carnivore Diet: What You Need to Know

If you haven't heard about the "all-meat diet" yet, it is time to get informed. Popularly coined the "Carnivore Diet", and also known as the "Zero-carb Diet", this approach to eating has gained heavy steam over the past year. An orthopedic surgeon was interviewed on a popular podcast, stating he has eaten only meat for over a year and claims to feel better than ever. Is the Carnivore Diet too good to be true? Or are we jumping to a fad diet conclusion too early before fully understanding the approach? Whatever the answer may be, let's get to the bottom of it.

What is the Carnivore Diet?

Honestly, it is very simple: you eat only meats from animals, nothing else. You don't eat veggies, fruits, grains, or anything of the like. Sounds extreme? That's because it is. It is one thing to consider a vegan diet where you cut out everything but plant-based foods, or a ketogenic diet where you cut carbs and focus solely on dietary fat (small portions of protein). But now we get told to cut out vegetables and fruits because eating only meat is the healthiest way to go? As trainers, we're used to focusing on a balanced diet, so we need to get more information.

What Foods Make Up This Diet?

To be specific, we are looking at steaks, ground beef, and red meat—the fattier types of animal protein—to make up the bulk of the calories consumed following this approach. Since you're not eating any carbohydrates or vegetables, your calorie intake is going to be severely cut if they were previously part of your regular diet, so filling them in with fattier cuts will be easiest. Additionally, poultry, fish, bacon, sausage, whole eggs, bone marrow, and even some dairy products like milk, cheese, yogurt, and butter are all approved since they all come from animals. However, most of the carnivore dieters who blog about this and really brought it to life say they either omit the dairy or limit it to very small amounts. One popular blogger-turned-nutrition-coach simplified her diet even more and eats only beef.

Don't You Still Need Vegetables and Nutrients?

You might be wondering, "Okay, so meat for every meal, but wouldn't that make me deficient in vital nutrients like certain vitamins and minerals? Don't I need veggies in my diet?" A great question indeed. However, those that follow this approach say no supplements are needed. If you are eating strictly animal proteins, it's expected that you should be getting all the amino acids, creatine (red meat), and vital micronutrients you need. The theory behind this is if the animals you consume eat a healthy diet of fruits and vegetables, they digest and absorb those nutrients and pass them onto you when you eat them. If there is no deficiency in their diet, there will be no deficiency in yours and therefore, no need to supplement.

Is the No-Carb Diet Too High in Protein?

Many opponents of the carnivore diet say that too much protein is bad for your body, that it damages your kidneys and can weaken your bones. But that isn't what the research says. In ISSA's article, How Much Protein Do I Need: Protein Myths Busted, we cover this topic and present you with the science behind why these claims are simply not true.

Are There Benefits to the Carnivore Diet?

The first thing we need to address is that the benefits discussed here seem to be mostly anecdotal, meaning they are brought to light from others' personal experience from following this diet. At the time of this writing, only one study was found that looked at subjects who ate a strictly "all meat" diet for an extended period of time (one year). Other than that study, we really have no concrete evidence to support the benefits. There is no hard science out there to define how to optimally set up a carnivore diet, what benefits have been observed through reliable science, or whether it is healthy.

However, if we are listening to the personal accounts and anecdotal support, this diet results in:

• Weight loss

• Better heart health

• Lower inflammation

• Higher testosterone

• Fewer digestive problems

• Increased mental clarity

• Simpler ways of eating (macros, caloric intake, etc.)

Can This Really Be Good for Cholesterol and Heart Health?

To support the "better heart health" benefit, you need to dig deep into the scientific studies and not be swayed by popular media and conventional news. Newer research continues to debunk the statements of "saturated fat leads to heart disease" and "high cholesterol leads to cardiovascular attacks." Malhotra, Redberg, and Meier (2017) report that, "replacing saturated fat with linoleic acid containing vegetable oils increased mortality risk despite significant reductions in LDL and total cholesterol." Also, in 7,500 high-risk patients, an unrestricted Mediterranean diet (41% fat) coupled with at least four tablespoons of extra virgin olive oil or a handful of nuts resulted in a significant 30% reduction in cardiovascular events, compared to a "low fat" diet (Malhotra et al., 2017).

Malhotra et al. noted that, "a recent systematic review concluded that LDL cholesterol is not associated with cardiovascular disease and is inversely associated with all-cause mortality. A high total cholesterol to HDL ratio drops rapidly (a positive benefit) with dietary changes such as replacing refined carbohydrates with healthy high fat foods." Increasing healthy dietary fat intake to reduce cardiovascular-related events isn't blasphemy, it is supported.

Now, remember that ONE study mentioned earlier? Well, it was conducted in 1930 by researchers Walter McClellan and Eugene Du Bois. They had two men live on an exclusive meat diet for one year. The relative amounts of lean and fat meat ingested were left to the men's instinctive choice and protein content varied from 100 to 140 grams, fat from 200 to 300 grams, and carbohydrate (derived entirely from the meat) from 7 to 12 grams.

Their results after one year on the diet? The two men were mentally alert, physically active, and showed no physical changes in any body system; their weights remained constant, except during the first week where they lost weight due to the water content shift in the body; one man's blood pressure remained constant, while the other's systolic dropped 20 mmHg; bowels were not disturbed; vitamin deficiencies did not appear; no evidence of kidney damage via urine examination and determinations of the nitrogenous constituents of the blood; and clinical observations and lab studies showed no evidence of any ill effects from the prolonged use of the exclusive meat diet" (McClellan & Du Bois, 1930).

Is Eating ONLY Meat Healthy?

A lot of people can come to the conclusions that this type of diet seems unnecessary and unhealthy. However, those conclusions would come from opinion. Is it healthy? Well, since it is similar to the ketogenic diet, and research shows that fat is not to blame for heart disease, for now, it could be fair to say that this way of eating is not unhealthy. The absolute truth is that we do not know. There has not been any type of scientific evidence showing the benefits or risks for this way of eating. More studies need to be conducted over extended periods of time—following subjects for 5, 10, and 20 years—so that we can understand the long-term reciprocations for this diet.

Is the All Meat Diet Safe for Weight Loss?

It is important to remember that all fad diets end in a crash and burn scenario. When an individual restricts any macronutrient from their diet, they will lose weight initially, because they have simultaneously restricted the calories they would have eaten from that macronutrient. The moment they begin eating the way they did before, they will gain back all the weight lost and probably a few extra pounds. The same will be true for this diet. We've covered this idea of weight loss and energy balance in the article, Best Diet For Weight Loss?

Dr. Spencer Nadolsky, known as ‘The Doc Who Lifts', is a physician specializing in the treatment of obesity. He says this diet is, "certainly not optimal," and wouldn't be considered a "healthy" way to lose weight unless that meant a person couldn't lose weight on a more plant-based diet for some reason. In his recommendations to clients, he often advocates for lean cuts of beef, rather than the fatty cuts recommended by the diet and even suggests his clients replace animal protein with beans or legumes to save a bit of money in their budgets.

In closing, this is not an indication of support for this diet nor a suggestion to try it out with your clients. As trainers, we know vegetables are powerful and healthy; fruits are great sources of vitamins, minerals, and antioxidants; and that the occasional bowl of ice cream supports long-term commitment and sustainability. However, it is important to stay up-to-date on the new and popular diets so you can discuss them with clients, should the need arise. Do your own research and continue to be students and passionate learners of all things health and fitness related. For more information on coaching clients on nutrition, explore the ISSA's Nutrition Certification Course.

References

McClellan, W., & Du Bois, E. (1930). Clinical Calorimetry: Prolonged Meat Diets With A Study Of Kidney Function And Ketosis. Journal of Biological Chemistry,651-668. Retrieved September 1, 2018, from https://www.jbc.org/content/87/3/651.full.pdf

Malhotra, A., Redberg, R., & Meier, P. (2017). Saturated fat does not clog the arteries: Coronary heart disease is a chronic inflammatory condition, the risk of which can be effectively reduced from healthy lifestyle interventions. British Journal of Sports Medicine,51(15). Retrieved September 1, 2018, from https://bjsm.bmj.com/content/51/15/1111.