by Natalie Logan, RD, LD
Ever wondered if you have a fast or slow metabolism?
Have you ever heard someone say, “My metabolism must be slow because I’m not losing any weight”? Some people who are trying to lose weight and can’t seem to get the pounds to budge tend to blame their metabolism for working improperly. Even though studies show that your metabolism will decline with age, it’s at a slow rate and not enough to cause you to gain or maintain an unhealthy weight.
Metabolism is the process of combining food with oxygen to release energy our body needs to function. Total metabolism represents the calories needed for maintaining body functions, lifestyle activities (i.e. work, play) and exercise. Your resting metabolic rate (RMR) represents a portion of total metabolism and refers to the calories the body burns to maintain vital body functions (breathing, heart rate, brain function). In other words, it’s the calories you need if you were to sit on your couch and do nothing but rest all day.
RMR accounts for about 75% of the calories a person burns all day. Therefore, if you were trying to lose, gain or maintain your weight, knowing your RMR is a crucial piece of information to help determine how many calories your body needs to reach your weight goal.
RMR is influenced by a number of factors: body composition (amount of fat & muscle), body mass, gender, age and hormones. People who weigh more and/or have more muscle (because muscle burns more calories than fat) will have a higher metabolism. Unfortunately, most people will have a 2-3% decline in their metabolism every decade, primarily due to a decrease in muscle mass. Men typically have a higher metabolism than women, partly because they tend to have a higher muscle mass compared to women. Certain hormones and other substances (caffeine, nicotine, medications, & nutritional supplements) can increase or decrease metabolism. Your stress level, an injury or an illness can also impact your metabolism.
Typically, when you lose weight, your metabolism will decrease. This is no surprise because the reduction in metabolism is a result of tissue loss. During weight loss, your body may also lower the metabolism in response to your lower overall calorie consumption. Losing the initial few pounds can be easy, and then your weight may plateau. This would be a good time to have your RMR tested again because your body doesn’t need as much fuel to function, and it isn’t necessary to continue eating as many calories as you did before the weight loss.
Staying active and building muscle is important for overall health and well-being and increasing your metabolism. Your physical activity (strength training & cardio) are factored into the total amount of calories you can consume for your weight loss goal. Bottom line– weight loss is a result of calories consumed and calories burned.
So your “slow” metabolism may not be why you didn’t reach your weight loss goal. If you truly want to solve the weight loss mystery and know how many calories your body needs, it’s time to have your metabolism determined. NPPT offers metabolic testing with the Korr Medical metabolic machine. This machine determines your unique resting metabolic rate and is accurate so it will help you to begin an individualized calorie meal plan that’s made specifically for you.