What Makes Your Metabolism Unique?
Women generally have slower RMRs than men, mostly because of their typically smaller frames and less muscle mass. People who are naturally larger framed and muscular have relatively fast RMRs. Thus, the most important genes affecting your metabolism are the ones that influence your frame size and muscle mass.
Having a slower RMR than someone else is not a problem unless you try to eat as much as they do. Your body simply doesn’t need as many calories to function. The RMR of a non-exercising adult typically decreases 2 to 5 percent every decade, mostly due to lack of physical activity and loss of muscle and organ mass. This trend is reversible. You can boost your metabolism at any age with muscle-building exercises.
Losing weight can also decrease your RMR, primarily because when you lose weight, you usually lose some muscle as well as fat, and the lost muscle and fat are no longer using calories. Proper muscle-building exercises during a period of gradual weight loss can help preserve your muscle mass and keep your metabolism up.
Your daily activities also affect your metabolism. In addition to the calories burned by resting metabolism, a non-exercising adult will burn about 20 percent more calories each day moving around, digesting food, and maintaining body temperature. A moderately active adult (for example, one who plays an active sport or exercises three to five days a week) will burn a total of about 50 percent more calories.