Many people wonder what is metabolism and what factors can affect your metabolism rate.
A simple definition of metabolism is: the process by which your body converts what you eat and drink into energy.
During this complex biochemical process, calories in food and beverages are combined with oxygen to release the energy your body needs to function. So your metabolism is the amount of energy or calories that you need daily to keep your body functioning and to do physical activity. Your body requires energy for 3 basic purposes – fueling essential body functions, processing food and doing physical activity.
Your resting metabolic rate (RMR) is the calories needed for necessary functions such as regulating body temperature, breathing, circulating blood, adjusting hormone levels, and growing and repairing cells. RMR accounts for ~60-70% of total calories. Thermogenesis or food processing which includes digesting, absorbing, transporting and storing food accounts for ~10% of our daily calories. For the most part, the body’s required calories to process food stays stable and aren’t easily altered. Fuel needed for physical activity accounts for another 20% of metabolism.
Factors that Affect Your Metabolism
In talking with my clients, I find that there is a lot of confusion about metabolic rate and lifestyle changes to make our body burn calories faster. There are a variety of factors that determine your metabolic rate. Some of these variables can be changed and then there are others that can not be influenced. Let’s look at the factors that keep our metabolism burning.
Factors that Determine Individual Metabolic Rate
Several factors determine your individual metabolic rate. Some factors like physical activity we can control, and others like sex, age and height, we can’t.
- Your sex. Men generally have more muscle mass than women of the same age and weight. Therefore, they burn more calories and consequently have a higher metabolism.
- Your age. As we age, the amount of muscle tends to decrease and fat accounts for more of our weight. The result is that we burn less calories and our metabolic rates are lowered. Beginning at age 30 and for each decade thereafter, the average person’s metabolism slows by 2-3%. Strength training exercises are important because they help to counteract the muscle loss associated with aging.
- Your body size and composition. The bodies of people who are larger or have more muscle, burn more calories, even at rest. You can’t make yourself grow taller, but you can do strength training exercises to increase your muscle mass.
- Your activity level. Physical activity helps burn calories and temporarily increase metabolic rate.
Most people are interested in their metabolism for weight management. Many people blame their increasing weight on a “slow” metabolism; however, in the majority of cases, the weight gain is simply the result of eating more calories than are needed. At Fairfax Nutrition, we can test your unique metabolic rate with a 10 minute breath test using the Korr Indirect Calorimeter. This test will tell you how many calories your body burns at rest and then we can calculate the calorie level to reach your goals.
Contact Deborah to Book an Appointment and get started on improving your nutrition and health.