No evidence that a carnivore diet leads to “90% reduction in all diseases” or treats diabetes

CLAIM

Carnivore diet produces “a 90% reduction in all diseases” and a reduction in insulin use by diabetics

VERDICT more about the rating framework

SOURCE: Mikhaila Peterson, YouTube, 8 Feb. 2022  

DETAILS

Unsupported: A study that reported health benefits of a carnivore diet was based on a self-perception survey. As such, the findings of the study were susceptible to various biases, such as recall bias, reporting bias and selection bias. Furthermore, the study didn’t examine factors that could influence the health status of respondents, and so it cannot be used to support the bold claim made by Peterson.

KEY TAKE AWAY

There isn't solid evidence that a carnivore diet is beneficial to health. A study that reported health benefits of a carnivore diet was based on a self-perception survey. However, studies based on self-reports are affected by multiple biases, such as recall and reporting bias. The study also didn’t measure respondents’ nutrition levels to verify respondent’s reports. These limitations raise questions about the objectivity of the study and its reliability. Excessive consumption of red meat and lack of vegetables in the diet can cause health problems, like higher risk of heart disease and certain types of cancer.

FULL CLAIM: Carnivore diet produces “a 90% reduction in all diseases” and a reduction in insulin use by diabetics

A carnivore diet consists of exclusively consuming foods of animal origin, including meat, fish, seafood, eggs, milk, and dairy products such as cheese and yogurt. In the video, Peterson cited a study that reported health benefits of a carnivore diet, claiming that participants reported a reduction in medication for diabetes and “a 90% reduction in all diseases”^[1].

However, this study has several limitations that affect the reliability of the conclusions, which we will explain in this article.

Peterson overlooked several limitations of a study on the self-perceived effects of a carnivore diet

The study cited by Peterson, published in the journal Current Developments in Nutrition in 2021, consisted of a social media survey of over 2,000 adults who self-identified as following a carnivore diet for at least six months^[1].

Survey respondents didn’t follow a standardized diet. Eighty-five percent consumed red meat daily, while less than 10% reported consuming vegetables more frequently than monthly, and only 37% didn’t take vitamin supplements.

The study aimed to assess perceived health changes since starting the carnivore diet, perceived adverse events, and respondents’ satisfaction with the diet. According to the authors, respondents reported high levels of satisfaction and improvements in overall health related to a carnivorous diet.

Respondents with diabetes reported benefits that included a reduction in medication use, including some who stopped using insulin. Respondents also reported positive changes for some chronic conditions, in particular obesity, hypertension, and cardiovascular problems, among other conditions included in the survey.

However, the study had several major limitations, which the authors acknowledged, but which Peterson didn’t mention. First, the survey assessed the perception of respondents following a carnivore diet, but didn’t actually measure nutrient levels in respondents, or independently verify the respondents’ self-reported health-related outcomes or health-associated behaviors.

The authors of the study warned that self-reported data are prone to recall and reporting bias, as “participants may have started the diet during a time of poor health and perceived subsequent regression to the mean as a benefit of the diet”, which can lead to “over-reporting of adherence and perceived beneficial effects” of a carnivore diet.

Second, there was likely a selection bias among respondents, as “individuals who experienced adverse effects or lack of health benefits are likely to have abandoned the diet and would therefore not have been captured in this survey”. The authors also noted that “adults adhering to a carnivore diet and responding to this online survey represent a special subpopulation with high levels of motivation and other health-related behaviors (e.g., physical activity, consumption of relatively whole, unprocessed foods)”.

The authors of the study warned that “respondents likely differ from the general population in ways that could influence the effectiveness, practicality, and safety of a carnivore diet”. The authors also noted that they hadn’t obtained detailed information on diet and lifestyle habits prior to starting the carnivore diet. Thus, the study wasn’t able to reliably establish a baseline to compare a person’s state of health before and after starting the carnivore diet. Without this, it is difficult to objectively determine whether someone’s health did improve on the carnivore diet.

Overall, the results of this survey should be taken with caution, as it isn’t possible to generalize the health benefits reported by the respondents to the public at large.

Health Feedback reached out to the authors of the study for comment and will update this review if new information becomes available.

While there isn’t evidence that following a carnivore diet has any health benefits, excluding plant-based foods from the diet can be detrimental to our health. Excessive consumption of meat can increase blood levels of “bad” cholesterol, which increases the risk of heart disease. Furthermore, excessive consumption of red meat has also been associated with higher risk of certain types of cancer^[2,3].

As Health Feedback explained in this insight article, a diet based exclusively on meat consumption, such as the one Peterson recommends in the video, can have several negative health repercussions.

Conclusion

There isn’t reliable evidence that a carnivore diet is beneficial to health. On the contrary, there is evidence showing that such a diet which excludes plant-based foods is harmful to our health. Peterson cited a survey that reported self-perceived benefits of the carnivore diet, overlooking several major biases in the study. Furthermore, the authors warned that their results shouldn’t be generalized, as the survey population is likely very different from the general population.

REFERENCES

• 1 – Lennerz et al. (2021) Behavioral Characteristics and Self-Reported Health Status among 2029 Adults Consuming a “Carnivore Diet”. Current Developments in Nutrition.
• 2 – Chan et al. (2011) Red and Processed Meat and Colorectal Cancer Incidence: Meta-Analysis of Prospective Studies. PLoS One.
• 3 – Huang et al. (2021) Red and processed meat consumption and cancer outcomes: Umbrella review. Food Chemistry.