Low-Carb Diets Are the Best for Maintaining Weight Loss A new study suggests the best way to keep weight off is to eat less carbs. The BMJ study surveyed 164 overweight or obese people. Participants were put on a low, medium or high-carb diet for 20 weeks. We found that the type of diet people ate had a major impact on their metabolism. Those on the low-carbohydrate diet burned about 250 calories a day more than those on the high-carbohydrate diet. This suggests that all calories are not created equal. Restricting carbohydrates rather than calories seems to be ideal for weight loss. A low-carb diet could potentially lead to weight loss of about 20 pounds over a few years, without the need for calorie counting.