When people eat a low-fat, high-carb diet, their body burns less fat for energy overall, which might help explain why fat builds up in the blood.

Eating a low-carb diet makes your body burn more fat for energy, even if you don't change how many calories you eat or your weight stays the same. This happens over just a few weeks as your metabolism naturally shifts to use fat instead of carbohydrates.

After eating, people on a low-fat, high-carb diet have higher levels of fat, sugar, and insulin in their blood for longer than when they eat a diet with more fat, which might stress the body over time.

Eating fewer carbs and more fat—without counting calories—can help people lose about as much weight as eating less fat and cutting calories. This suggests that what you eat might matter just as much as how much you eat.

If you're overweight and eat fewer carbs instead of less fat for four weeks, you might lose more body fat—even if you lose the same amount of total weight as someone on a low-fat diet.

Eating fewer carbs and calories helps overweight people lose weight by improving how their bodies process energy. This finding is from the abstract summary - full study details were not available