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

Cutting back on carbs can improve important blood fat and cholesterol levels in overweight people with metabolic syndrome, even if they don't lose any weight. This means lowering carbs might fix the underlying metabolic issues directly, without needing to diet for weight loss.

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

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.

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.

For athletes who need to make weight (like wrestlers or boxers), eating low-carb and high-fat for a long time might help them lose fat without losing muscle, which is safer than starving or sweating off weight quickly.