In the simplest terms, “Metabolism is the process by which your body converts what you eat into energy,” Casey Kelly, MD, ABOIM, functional physician and founder of Case Integrative Health, tells mbg.

This energy (i.e., calories) is used or “burned” to fuel the body’s basic functions, such as breathing, circulation, and nutrient absorption.

It also provides energy for complex physiological reactions (including DNA synthesis, RNA transcription, and neuronal cell signaling in the brain), as well as activities that require more energy (such as immune function, healthy inflammatory responses, and physical activity).

Needless to say, your metabolism is affected by a many.

Metabolism is closely related to your metabolic rate or the energy/calories you use or “burn” each day. Metabolic rate also depends on: