Claim: The “Living Carnivore” Diet is Good for Weight Loss

Verdict: Broadly true, but misleading

“Within 30 days I lost 20 pounds. JD Vance is also on the diet and you can see how different he looks.”

“The way that you're supposed to eat it is bite for bite. You take a bite of the meat, you take a bite of the sauerkraut”

RFK Jr.

After Vice President JD Vance credited his weight loss to RFK Jr’s recommended “meat and sauerkraut” diet, the “Living Carnivore” diet has been under the spotlight. But does it really work?

The Good News: Weight Loss is Reasonable

For the goal of weight loss – without considering other issues – and despite no direct evidence on the Living Carnivore diet specifically, it doesn't seem too bad. This largely comes down to the benefits of eating fermented foods. Generally speaking, there are multiple benefits to consuming fermented foods, as shown by a study using data from the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2018.

The study found that each 100 g of microbe-containing foods was associated with reduced BMI, waist circumference, systolic blood pressure, C-reactive protein, plasma glucose and triglyceride, and increased high density lipoprotein cholesterols. The mechanisms of action get a little complicated, but generally include influencing gene expression, slowing gastric emptying and modulation of the gut microbiome.

The carnivore side of the diet is where the problems come in. Purely for weight loss, there is some evidence that they can lead to weight loss and increased satiety.

The Bad News: Nutrient Deficiencies and Cholesterol

A 2026 scoping review focused on the carnivore diet noted these benefits for weight loss, but stressed the “substantial risks” of nutrient deficiencies. Overall, the carnivore diet can lead to deficiencies in thiamine, vitamin C, vitamin D, magnesium, iodine, potassium, calcium and fibre. The deficiency in fibre is also pretty extreme, at less than 1/25th of the adequate intake. It's debatable whether you could rectify these issues by adding fermented foods.

Perhaps unsurprisingly, low-density lipoprotein cholesterol and total cholesterol generally increase, carrying risks of heart disease, and some versions have high sodium, potentially leading to high blood pressure and more.

And it should go without saying that eating “bite for bite” is probably useless, it takes a long time to digest food, relative to actual eating process. It all hits your stomach basically simultaneously anyway.

Overall, the diet – especially fermented foods – could help weight loss, but it’s terrible as an overall diet.