If you have metabolic issues like high blood sugar or cholesterol, eating foods that swap out butter or fatty meats for carbs (like bread or rice) or for olive oil and avocados doesn’t make a noticeable difference in your blood fat levels after meals.

If you swap out butter and fatty meats for foods like olive oil and avocados instead of swapping them for bread or sugar, your blood fat levels drop more — and that’s especially true if you already have health risks like high cholesterol or insulin resistance.

If you're at risk for metabolic problems, swapping butter or fatty meats for olive oil or avocados doesn't drop your 'good' cholesterol as much as swapping them for bread or sugar.

If you swap out butter and fatty meats for bread, pasta, or olive oil, your blood might show higher levels of a type of fat particle called lipoprotein(a), which could be a concern for heart health — carbs raise it more than olive oil.

If you're a man who's keeping your weight steady and eating very few carbs, doubling the amount of butter and fatty meats you eat won't raise the level of saturated fat in your blood — meaning carbs might be the key link between what you eat and what shows up in your blood.

Eating a diet low in fat and high in carbs makes the body less able to clear fat from the blood, causing triglyceride levels to rise sharply.