Behavioral Characteristics and Self-Reported Health Status among 2029 Adults Consuming a “Carnivore Diet”

Abstract

Background The “carnivore diet,” based on animal foods and excluding most or all plant foods, has attracted recent popular attention. However, little is known about the health effects and tolerability of this diet, and concerns for nutrient deficiencies and cardiovascular disease risk have been raised. Objective We obtained descriptive data on the nutritional practices and health status of a large group of carnivore diet consumers. Methods A social media survey was conducted March 30 to June 24, 2020 among adults self- identifying as consuming a carnivore diet ≥ 6 months. Survey questions interrogated motivation, dietary intake patterns, symptoms suggestive of nutritional deficiencies or other adverse effects, satisfaction, prior and current health conditions, anthropometrics, and laboratory data. Results A total of 2029 respondents (median age 44 years, 67% male), reported consuming a carnivore diet for 14 (interquartile range 9–20) months, motivated primarily by health reasons (93%). Red meat consumption was reported ≥ daily by 85%. Under 10% reported consuming vegetables, fruits or grains > monthly, and 37% denied vitamin supplement use. Prevalence of adverse symptoms was low (<1% to 5.5%). Symptoms included gastrointestinal (3.1–5.5%), muscular (4.0%), and dermatologic (1.1–1.9%). Participants reported high levels of satisfaction and improvements in overall health (95%), wellbeing (69–91%), various medical conditions (48–93%) and BMI (from 27.2 [23.5–31.9] to 24.3 [22.1–27.0] kg/m2). Among a subset reporting current lipids, LDL-cholesterol was markedly elevated (172 mg/dL), whereas HDL-cholesterol (68 gm/dL) and triglycerides (68 mg/dL) were optimal. Participants with diabetes reported benefits including reductions in BMI (4.3 kg/m2, 1.4–7.2), HbA1C (0.4%, 0–1.7), and diabetes medication use (84–100%). Conclusions Contrary to common expectations, adults consuming a carnivore diet experienced few adverse effects and instead reported health benefits and high satisfaction. Cardiovascular risk factors were variably affected. The generalizability of these findings and the long-term effects of this dietary pattern require further study. Summary In a survey of over 2000 adults following a “carnivore diet” (i.e., one that aims to avoid plant foods), health benefits and satisfaction were generally reported.

Reply to R Kirwan et al.

“…They advise caution in translating the results of our survey, which includes self-reported data, on the health effects of a carnivore diet. We agree with these concerns, as explicitly stated in our report ( 2 ). However, several specific criticisms of our study relate more broadly to scientific surveys and to nutrition research in general.…”

Unprocessed red meat in the dietary treatment of obesity: a randomized controlled trial of beef supplementation during weight maintenance after successful weight loss

“…In that study, twice as many participants withdrew from the “meatless” diet than the red meat diet, but differences in attrition were not statistically significant ( 25 ). These observations raise some concern about the feasibility of reducing or excluding red meat from the diet, because this food is particularly popular in industrialized countries ( 38 , 39 ) and accounts for about half of all meat consumption in both sexes and all age groups ( 12 , 13 ).…”

Was there a need for high carbohydrate content in Neanderthal diets?

“…To gain further insights into the possibility for keto‐adaption in Neanderthals I would encourage future experimental research in human subjects consuming very low carbohydrate diets excluding all food groups that would not have been available to Paleolithic humans. Diets such as the “Paleolithic Ketogenic Diet” (Clemens et al, 2018; Clemens & Tóth, 2019), “Carnivore Diet” (Lennerz et al, 2021) or “Zero‐carb diet” (Protogerou et al, 2021) have recently gained popularity among certain social groups, which provides a unique opportunity to study human metabolism and the possibility to “thrive” on such diets. I agree with Chang and Nowell (2016) who proposed to use the popularity of Paleolithic diets to start a dialogue between the public and evolutionary scientists, and I propose to especially include Paleolithic‐type diets with high meat content or completely excluding plants.…”