Routinely squeaking by on five hours or less per night increases visceral fat levels, according to a 2010 Wake Forest University study. What’s more, after analyzing 28 different studies, UK researchers found that people who slept 5.5 hours or less per night ate an extra 385 calories the day after compared to those who snoozed for at least 7 to 12 hours. On top of that, they preferred to munch on fatty foods full of empty calories, like chips.
The prevailing formula for a long time on how much fat you’re going to burn was calories in minus calories out, based on your basal metabolic rate (BMR) and exercise efforts, explains strength and performance specialist Joel Seedman, Ph.D., owner of Advanced Human Performance in Atlanta. But with all the different biochemical reactions in the body, hormonal response, and endocrine function, there are an infinite number of factors that can affect how your body is storing and breaking down calories.