You crank up the heat.
To fry fat, dial down the thermostat. Participants who slept in bedrooms cooled to 66°F for a month doubled the amount of brown adipose tissue—a type of fat that burns rather than stores calories, researchers at the National Institutes of Health found. “Brown fat becomes more active in cooler temperatures to help keep us warm,” says Aaron Cypess, MD, an endocrinologist at the NIH. So the more active your brown fat, the more calories you’ll burn throughout the day. While it’s too early to say how long you need to spend in the cold to reap the calorie-burning rewards, turning down your heat, sleeping in cooler temps, and spending time outdoors (Cypess forgoes a coat when it’s 55°F and over) may make a difference.
You’ve completely cut out carbs.
True, study after study shows that for weight loss, a low-carb diet trumps a low-fat one. But that doesn’t mean you should eliminate carbs completely, especially if you exercise regularly. “During exercise, your muscles demand glycogen from carbohydrate stores in your body,” St. Pierre says. “If you don’t consume enough carbohydrates, your glycogen levels will be too low and you won’t have the energy to exercise as intensely.” As a result, you’ll burn fewer calories during your workout as well as post-exercise since your body won’t require as much energy to recover. His advice: consume a serving of carbs (about the size of one cupped palm) such as oatmeal, brown rice, or sweet potato at each meal.