People with high triglycerides process fat differently than those with normal levels when eating a low-fat, high-carb diet — their bodies use different fat sources and clear fat slower, which may explain why this diet raises their triglycerides more than it does in others.

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.

In people with high triglycerides, a low-fat high-carb diet changes where the fat in their blood comes from — but scientists still can't explain where about 1 in 5 of those fat molecules are coming from.

Almost everyone who switched to a low-fat, high-carb diet saw their blood fat levels go up—only one person didn’t, which means this effect happens in nearly all people.

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.

When you swap fats (like butter or oil) for carbs (like bread or sugar), your blood fat levels (triglycerides) tend to go up.