A 2022 study published in Nature Medicine of 52,000 women and men, found just one common factor in every overweight man and woman: low brown adipose tissue levels! Brown adipose tissue, called BAT, also known as brown fat, is not fat at all. It’s not a fat storer but a fat shrinker. Its brown color comes from its densely packed mitochondria which work 24/7 to burn calories from your fat stores and the food you eat into pure, natural energy. Even though BAT makes up a fraction of your weight, it can burn up to 300 times more calories than any other cell in your body.