You might hear someone refer to their own metabolism as being “slow” or “fast.” These distinctions, while simplistic, are generally true for most of us. The speed or efficiency of our own metabolisms, also called a basic metabolic rate (or BMR), is largely out of our control. It’s what our bodies do all by themselves and when we are at rest. Your BMR is determined by your genes.
We all know that person who can eat anything and never seem to gain any weight. Their body has a BMR that tends to burn through calories faster than others. A slower BMR can result in more calories sent off for storage in the form of fat.