Whether you cut fat or carbs, if you eat the same number of calories, you’ll lose about the same amount of weight.

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 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 less fat for four weeks, you might lose more muscle than fat compared to someone who eats fewer carbs — even if both diets help you lose weight.

If you're overweight and eat fewer carbs instead of less fat for four weeks—without counting calories—you might lose about 8 pounds more than someone on a low-fat diet, and it might be because you're losing more body fat.

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