Meanwhile, inactive muscle and brown fat use little energy: One pound (0.45 kilogram) of relaxed muscle burns 6 calories and the same amount of fat burns 2 calories in a day. But because muscle is ...

One pound (0.45 kg) of inactive muscle burns 6 kcal per day, while the same amount of fat burns 2 kcal. Muscles can also burn a significant amount of calories when they're active: A 2015 study ...