Carnivore Diet 2023: Is The All-Meat Diet Safe & Healthy?

The carnivore diet is a restrictive diet with a no-carbohydrate (carb)  feature and aspects of the keto diet^[1]. In carnivore dieters, the main idea is eating nothing but animal-based products such as all kinds of meats, eggs, and dairy products. These foods are all high-protein foods without a doubt.

First, we should mention that such a restrictive diet may lead to many vitamin and mineral deficiencies. Also, chronic diseases and metabolic stress are reflective of high animal product consumption, primarily due to meat. Yes, animal products are also beneficial and have a lot of nutritional benefits; however, too much of a good thing is not necessarily true when it comes to large quantities of these foods. 

A carnivore diet is a high-protein diet that has been known to cause kidney problems, high cholesterol, heart disease, cancer, malnutrition, low calcium, and intestinal inflammation. So, let’s take a closer look at the benefits and side effects of such a diet.

What Is The Carnivore Diet?

This diet is also called the “meat-only diet.” People who follow this diet eat meat, fish, poultry, or dairy products like carnivorous animals eat; thus, it is called a “carnivore diet”. People who follow this diet generally do it to try to lose weight.

You may think following the carnivore diet is similar to the ketogenic diet or low-carb diet, and although it is a form of a ketogenic diet, there are many differences.

Keto diets include some plant-based products such as nuts and legumes. Also, people can eat a particular amount of vegetables while on keto and paleo diets. However, you can not consume nuts and other plant-based foods in this carnivore diet.

Can You Have Too Much Meat?

Eating meat is delicious and nutritious for us. But how much meat can a person eat? This is the question we need to answer. 

A person consumes 0.8-1 gram of protein per kilogram (kg) in a standard diet. If we think about a 70-kilogram male, he consumes 56-70 grams of protein. This amount of protein can come from; 

• One piece of steak^[2] (4 oz=113 grams and includes 33 grams of protein)
• Two eggs^[3] (13 grams of protein)
• Two cups of milk/yogurt^[4] (16 grams of protein) 

A person can consume the rest of the protein from plant-based products such as bread, grains, nuts, seeds, and veggies during the day.

However, in carnivore diets, you may multiply this protein amount by two or three times because the diet can’t contain other plant-based products. It increases the daily protein intake dramatically when you eat only meat. 

The protein and animal fat overload may affect the liver, kidney, heart, and whole body.

There is no evidence-based result about this diet. Still, we can examine the general protein overload and health effects of animal product consumption from scientific studies to understand carnivore diet effects. 

Carnivore Diet Food List: What To Eat & Avoid

The carnivore diet consists of the following foods:

• Meat; Beef, Pork, Bison, Lamb, Moose, Venison, and their organ meats 
• Poultry: Chicken, Duck, Turkey
• Fish and seafood: Shrimp, Squid, Lobster, Oysters, Crabs, Scallops, Salmon, Tuna
• Eggs
• Dairy Products: Milk, Full-fat cheese, Yogurt, Butter
• Beverages: Water, tea, coffee, bone broth

Food groups that are forbidden: 

• Vegetables
• Fruits
• Nuts
• Grains
• Seeds

It is also a low-carb diet. However, we call it zero carbs because this diet’s only carb comes from dairy products. Due to the carbohydrate content of dairy products, carnivore eaters don’t prefer to consume too much. The all-meat diet is an extreme elimination diet similar to the keto and paleo diets with the exception of all plant foods.  

Health Benefits Of The Carnivore Diet

Now, you may wonder health benefits of a carnivore’s diet. It is undeniable that meat contains many essential nutrients such as heme iron, Vitamin B12 with other B vitamins, zinc, phosphorous, selenium, and protein that is easily absorbed. 

Weight Loss

Carnivore eaters tend to the idea that carbohydrates are very harmful. However, seeing all carbohydrates as the same is not the right approach. The strict carnivore diet reduces body weight, high blood sugar, and insulin levels. The main idea behind the carnivore diet is similar to that of the keto diet. 

Diet-related heat production (thermogenesis), blood amino acid concentration, liver sugar production (gluconeogenesis), and production of ketone bodies (ketogenesis), all result from an increase in diets with high meat and protein consumption. This situation contributes to the feeling of satiety. Therefore, it can be effective in weight loss^[5].

A zero-carb diet aims to reduce body fat by these mechanisms. Animal protein bar also helps to minimize muscle loss while you are losing weight. 

Blood Sugar Regulation

The meta-analysis^[6] of 12 articles, including 1,138 type 2 diabetes patients, showed that a high protein diet didn’t reduce fasting blood sugar. Still, it has a positive effect on insulin resistance. The underlying mechanism^[7] might be that high protein intake improves biochemical signals for insulin sensitivity and pancreas beta-cell function, where insulin production occurs. 

However, a well-conducted randomized clinical study^[8] showed no significant difference in weight loss and biochemical parameters such as blood sugar, insulin, and blood fat levels. 

Mental Function

The amino acids found in animal products are essential nutrients for producing neurotransmitters^[9], the chemicals for our brain and neuronal activities. 

A meta-analysis^[10] examines the relationship between meat intake and mental health. The results show meat avoidance could negatively affect psychological health. The prevalence or risk of depression or anxiety was higher in participants who avoided fatty meat or meat consumption. However, the reason behind the avoidance behavior might be social outcomes should be examined in more detail.

The data obtained from 493,888 UK Biobank participants showed that dementia and Alzheimer’s disease^[11] risk decreases with the increase of unprocessed red-meat consumption of 50 grams per day. However, we should consider that an increase of 25 grams daily of processed meats was associated with an almost 1.5-fold increased risk of dementia and Alzheimer’s disease. 

Carnivore Diet Side Effects

Is the carnivore diet safe? Not exactly… Adverse health outcomes of carnivore diets are due to metabolic imbalances in the body. A meta-analysis^[12] investigating the effects of meat consumption on mortality risk indicates that excessive red and processed meat consumption increases in all-cause mortality.  

However, another study of subjects who had followed the carnivore diet works for six months, looked at lab parameters, self-reports of symptoms suggestive of nutrient deficiencies, diet satisfaction, prior and current health conditions, and anthropometrics. Participants reportedly displayed a high level of diet satisfaction, improvements in health and overall well-being, and a loss of weight. 

The only negative outcome from this survey of 2,029 subjects was a statistically significant elevation in low-density lipoprotein (LDL) cholesterol, or, as some call it, bad cholesterol. An increase in LDL results from the high-calorie intake of saturated fat coming from animal products in the carnivore diet, thus increasing the risk for heart disease.

Chronic Disease Risk

A review^[13] examining the high consumption of red meat, mainly processed meat, concluded that it increases the risk of many critical chronic diseases. For this reason, some European countries have recommended limiting red meat consumption in their new dietary guidelines.

Eating only meat makes your diet not only high in protein but also high in fat diet. As everybody knows, high saturated fat diets are one of the biggest reasons for chronic diseases, particularly heart. 

Cancer Risk

A comprehensive review and meta-analysis study^[14] conducted in 2021 from 128 studies showed meat consumption associated with different cancer types. Red meat increases the risk of breast cancer, endometrial cancer, colorectal cancer, colon cancer, rectal cancer, lung cancer, and hepatocellular carcinoma. 

People consuming processed meat tended to have a higher risk of 6% breast cancer, 18% colorectal cancer, 21% colon cancer, 22% rectal cancer, and 12% lung cancer.

The risk of gastric cancer^[15] increases for every 100 grams/day of red meat consumption. For every 50 grams/day increase in processed meat consumption, the risk of developing gastric cancer almost doubles.

According to the World Cancer Research Fund, consuming red and processed meat significantly increases colorectal cancer risk.

Heart Disease And High Blood Pressure

A comprehensive study^[16] examined 23,926 deaths during the annual follow-up of (2.96 million person-years) in two cohort studies. There was a reduction in cardiovascular and cancer mortality association by 7-19% in those subjects who substituted one healthy food choice (whole grains, low-fat dairy, fish, nuts, legumes) for one meat serving per day over four years.

Reducing animal fats for heart health is necessary because they contain a significant amount of saturated fat, which leads to an increase in heart disease morbidity and mortality. The latest review^[17] in 2022 showed that meat consumption is related to high blood pressure and vascular dysfunction. 

Not only are animal fats high in saturated fat, but they are high in cholesterol as well. The role of cholesterol in heart disease has been hotly debated, and limiting cholesterol to 300 mg daily as recommended by the United States Department of Agriculture, is hard to stick to on an all meat diet.

Kidney Disease

Consuming meat increases protein intake dramatically and, thus, the kidney load. The waste products of protein and urea, increase in the body and cause hyperuricemia. This is one of the major risk factors for the development or progression of chronic kidney disease.

Negative health outcomes of chronic high urea^[18] levels also include altering the intestinal barrier, disrupting molecular signals related to insulin resistance, increasing free radical production, and changes in cellular death.

Gastrointestinal Problems

Eating only meat means you don’t eat carbs, so dietary fiber^[19] intake is negligible. This leads to gastrointestinal problems such as constipation, bloating, irritation, and microbiota deterioration. In addition, the carnivore diet’s high inflammatory load can significantly damage the stomach and intestines. Thus, increased meat consumption is one of the most important causes of colorectal cancer.

Sustainability And The Meat-Only Diet

Meat products, especially red meat, are a high-quality protein and an intense source of calories, dietary iron, zinc, phosphorus, niacin, B6, and B12. However, the frequency of preference for meat consumption has increased due to the increasing global nutritional needs and the relationship of excess meat consumption with the pathophysiological mechanisms of chronic diseases.

It has been reported^[20] that greenhouse carbon emissions in the USA will gradually increase with meat consumption, especially in terms of beef, so red meat consumption should be limited for the sake of the environment.

Maintaining moderate meat is an important strategy to avoid nutrient deficiencies. Limiting meat consumption not only reduces the chronic disease risk but also may help global food security.

The National Diet and Nutrition Survey^[21] rolling program showed that meat consumption was reduced in the United Kingdom. From 2008 to 2019, average daily meat consumption decreased from 103.7 g to 86.3 grams, primarily in red meat and processed meat…

Carnivore Diet Meal Plan: Sample Menu

Since the Carnivore diet includes a limited amount of foods, the variety of meals is less. A daily carnivore diet plan can be:

• Breakfast:  Fried eggs in margarine
• Snack: Yogurt, mozzarella cheese sticks
• Lunch: Bone broth soup
• Snack: Cottage cheese; grilled steak strips
• Dinner: Chicken breast with melted cheese slice and chives

There are only carnivore diet recipes made from animal sources, but they also cannot provide variety in the diet. The carnivore diet has very limited snack alternatives. 

When you consume a large amount of lectin, it binds carbohydrates and creates a sticky layer for cells. It causes some harmful effects. Hemagglutination, sticking red blood cells together, is one of these effects. For this reason, a lectin-free diet aims to reduce lectins in the diet.

Pasture-raised meat is preferred in lectin-free diets due to its low lectin content. However, the carnivore diet is not generally suitable for a diet low in lectins. Conventionally raised meat and poultry are generally excluded from a lectin-free diet. Eating pasture-raised animal foods on a carnivore diet is very difficult and costly, so people often consume factory-made or processed animal foods.

The beneficial content that is taken from animal foods can be provided by protein supplements. This way, it is possible to have a normal nutritional pattern with fewer side effects and without following a carnivore diet.

Final Words

Although high protein, low carb diets are thought to be suitable for metabolic syndrome markers such as blood sugar, blood lipids, hypertension, and insulin levels, reliable meta-analysis studies are controversial. 

Since the carnivore diet contains the highest amount of animal foods among the high-protein diets, the potential for adverse effects is very high. It is a fact that high protein diets are effective in weight loss, but considering a zero carbs approach may have significant side effects both for our physiological health and environmental health; losing weight with this method may not be a good option.

There are many healthy diet alternatives that work as well as high protein diets for weight loss without resorting to the carnivore diet. The best path to a healthy alternative to the carnivore diet is to adopt a balanced diet adequate in calories for your weight goals in conjunction with an activity program.

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