Understanding your body’s metabolism is the first step toward achieving your overall health goals. Whether you want to lose weight, increase energy, or manage underlying conditions such as diabetes, knowing how your body’s metabolism functions are the first step down the path of any healthy-minded diet and lifestyle regimen. And in learning, you might be surprised by what you didn’t know about your metabolism.
First, it is essential to understand the metabolic process within the human body. Metabolism combines all the chemical processes that allow an organism to sustain life. For humans, this includes converting energy from food into energy for life-sustaining tasks such as breathing, circulating blood, building and repairing cells, digesting food, and eliminating waste. In short, metabolism is how your body uses the energy absorbed by consuming food (and beverages) to sustain life.
According to a Harvard University study, the minimum amount of energy needed to carry out these basic processes while an organism is fasting and at rest is known as the basal metabolic rate, or BMR, which can be calculated using a variety of online calculators that take into account an individual’s height, weight, age, and sex. BMR is often referred to as resting metabolic rate, or RMR. Total energy expenditure (TEE) is a combination of BMR plus energy used for physical activities and energy used to digest food (known as dietary thermogenesis). For sedentary adults, BMR accounts for about 50% to 70% of total energy output, dietary thermogenesis for 10% to 15%, and physical activity for the remaining 20% to 30%.
For adults in their 40s and 50s, the subject of metabolism and how it affects your overall health is filled with myths. The biggest is that the extra pounds you’ve put in as you age are caused by slowing metabolism. A new international study counters the common belief that our metabolism declines during our adult lives and is the culprit of unwanted weight gain. At least not until we reach our 60s.
Researchers found that metabolism peaks in the first year of life when babies burn calories 50 percent faster than adults. Then, the body’s metabolism gradually decreases at a rate of roughly 3 percent a year until around age 20. From there, metabolism plateaus until about age 60, when it slowly decreases again, but at a very low rate of less than 1 percent annually.
To further understand how to use the metabolic process for your personal health goals, here is a breakdown of how your body’s metabolism functions during different stages of your life. We must acknowledge these variations in energy expenditure that may affect a person’s weight trajectory or response to weight management strategies.
Adulthood (20 to 60 years): Total and basal expenditure and fat-free mass were stable from ages 20 to 60, regardless of sex. Adjusted TEE and RMR remained steady even during pregnancy, and the increase in body mass accounted for an increase in unadjusted energy expenditure. The point at which adjusted TEE started to decline was age 63, and for adjusted BMR was age 46.5 (although the researchers indicate a small number of BMR measurements reduced their confidence in this estimate).
Older adulthood (>60 years): At approximately 60 years old, TEE and BMR began to decline, along with fat-free and fat mass. However, declines in energy expenditure exceeded that expected from reduced body mass alone. Adjusted TEE and BMR declined by 0.7% per year, and for subjects 90 years old and more significant, adjusted total expenditure was about 26% below that of middle-aged adults.
It is important to remember that you can take control of how your metabolism works at any stage of your life. To achieve and maintain a healthy weight and boost overall health performance, here are some tips for applying to your daily routine:
· Eat a healthy, balanced diet consisting primarily of whole foods in the form of fruits, vegetables, lean protein, and whole grains
· Maintaining an active lifestyle with a goal of at least 150 minutes of physical activity a week, including strength training to increase or maintain lean muscle mass
· Get adequate rest, which for most individuals is seven to eight hours of sleep daily
· Manage stress through mindfulness, meditation, or other relaxing activities.