Keto Diet

In 1921, a distinguished physician at the Mayo Clinic suggested trying what he called a ketogenic diet, a high-fat diet designed to be so carbohydrate-deficient it could effectively mimic the fasting state. Oddly, the success of ketogenic diets against pediatric epilepsy seems to get conflated by keto diet proponents into suggesting it is beneficial for everyone.

By eschewing carbohydrates, you force your body to burn fat. And indeed, the amount of fat you burn shoots up when you eat a keto diet. At the same time, however, the fat you take in shoots up when you eat a keto diet. What happens to our overall body-fat balance? Body fat loss slows upon switching to the ketogenic diet.

Just looking at the scale, the ketogenic diet seems like a success, but what happens inside bodies tells a different story. On the keto diet, rates of body fat loss may slow by more than half, so most of what is lost is water. The reason less fat is burned on a ketogenic diet is presumably the same reason people who start fasting may start burning less fat: Without carbohydrates, the preferred fuel, our bodies start burning more of our own protein.

Inadequate intake of 17 micronutrients has been documented in those on ketogenic diets. Children have gotten scurvy, and some have even died from deficiency of the mineral selenium, which can cause sudden cardiac death. Bone fractures disproportionately plague children on ketogenic diets, along with growth stunting and kidney stones, and constipation is a frequently cited side effect. Keto diets have also been shown to reduce the richness and diversity of our gut flora, and all of that saturated fat can have a profound impact on the heart: A meta-analysis of four cohort studies following the diets, diseases, and deaths of more than a quarter million people found that those who eat lower-carb diets suffer a significantly higher risk of all-cause mortality, meaning they live, on average, significantly shorter lives.

The information on this page has been compiled from Dr. Greger’s research. Sources for each video listed can be found by going to the video’s page and clicking on the Sources Cited tab. References may also be found at the back of his books.