Eating very few carbs—like on a strict keto diet—can raise your 'bad' cholesterol, especially if you're replacing those carbs with lots of saturated fats like butter and red meat.

Eating fewer carbs might raise your 'good' cholesterol a little, especially if you replace them with fats or proteins, but it could also raise your 'bad' cholesterol, so it's not clear if this is truly helpful for your heart.

Eating fewer carbs might help boost good cholesterol and lower blood fats in people with higher body weight, but it doesn’t seem to change overall or bad cholesterol much.

If you're overweight and have high 'bad' cholesterol, eating fewer carbs for four weeks might help lower your bad cholesterol and improve your overall cholesterol balance better than eating low-fat, high-carb foods.

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 swap out butter or fatty meats for bread or pasta, your bad cholesterol goes up more than if you swap them out for olive oil or avocado — and the difference is pretty small, but it’s there.