Habitual low carbohydrate high fat diet compared with omnivorous, vegan, and vegetarian diets

It’s not just about eating less fat or less carbs—it’s more about whether the foods you eat are healthy (like veggies and whole grains) or unhealthy (like sugary snacks and processed meats).

People eating low-carb, high-fat food have about the same blood fat, sugar, and inflammation levels as those eating plant-based or meat-inclusive diets, so it doesn’t seem to hurt their short-term metabolism or blood sugar.

People who eat a lot of fat and very few carbs tend to have higher cholesterol numbers than those who eat plant-based or mixed diets, and more than 7 in 10 of them have cholesterol levels that doctors consider too high—especially if they’re eating super low-carb.

If you eat a lot of fat and very few carbs for half a year or more, the saturated fats in your diet tend to raise your bad cholesterol, while the monounsaturated fats might lower it — together, these fats explain about 40% of why your cholesterol levels go up or down.

People who eat low-carb, high-fat diets tend to eat way less fiber than vegans, vegetarians, or meat-eaters, and only 8% of them get enough fiber — but they still get enough vitamins because they take supplements.

People who choose to eat very little carbs and lots of fat tend to have worse eating habits than vegans, vegetarians, and regular meat-eaters—mainly because they eat fewer whole grains, fruits, and healthy fats.