- Metabolism, simply put, is the process whereby the body converts food sources into energy to utilize for basic functioning, tissue repair, or for storage in adipose tissue (fat) for future use as energy. If a person has a fast metabolism it means they burn calories (thermogenesis) more quickly and efficiently and store less as fat. A slower metabolism burns less calories, is less efficient and therefore stores more calories as fat. The metabolic rate can vary depending on several factors. The factors that are controllable include amount of regular exercise (amount of calories burned) and food intake (amount of calories ingested). Metabo Ultra-MaxTM is also Ephedra FREE.