Metabolism essentially means “burning calories to give your body the energy it needs.” There are 3 ways your body burns calories:
1. Resting metabolic rate (RMR): Your body needs to supply your organs with energy even while you do nothing, and that is RMR: the calories your body burns while at rest. It’s the energy you burn while sitting, sleeping, standing, etc.
2. Physical activity energy expenditure (PAEE): This is any energy burned while you are working out or doing any kind of activity. Whether you’re washing dishes, walking up the stairs, picking up a box, or lifting hundreds of pounds of weight, this is the PAEE. It’s all dependent on your activity during the day.
3. Thermic effect of food (TEF): When you eat, your body uses energy to digest food. It requires more energy than when you’re sitting with an empty stomach.