Several times a week I have conversations with clients about metabolism, how to speed it up, what can slow it down, and ways to boost it. There are some things that we can’t control when we talk about metabolism though...age, sex, and genes. When we get older, our metabolism tends to slow down because we naturally lose muscle, 5% each decade after 40, in fact. Men, who naturally have a higher ratio of muscle to fat, tend to burn up what they eat faster than women. Genes play a role as well. You are born with a certain body type. Some people just burn more calories than others.
Let’s get technical here for a second, so that we can try to fully understand metabolism. Metabolism is the way your body converts the food and drink you consume for energy and is usually measured in calories. The total amount of calories a person burns per day is known as total daily energy expenditure (TDEE) and it comes from several sources including resting metabolic rate (RMR), the thermogenic effect of food (TEF), non-exercise activity thermogenesis (NEAT), excess post-exercise oxygen consumption (EPOC), and exercise (Ex).
TDEE = RMR + TEF + NEAT + EPOC + Ex