Why Do Metabolisms Slow Over Time?
Posted by Center for Weight Loss Surgery
Why Do Metabolisms Slow Over Time?
Remembering when you were a teen and could eat nothing but pizza and donuts and stay rail thin can lead to a feeling of both nostalgia and despair. It might feel like your body is conspiring against you, punishing you just for getting older.
Perhaps you’ll find it reassuring that it’s normal for metabolisms to change as people get older, but you are not entirely a slave to your metabolism. There are steps you can take to both stave off and mitigate the effects of metabolic change.
What Is Your Metabolism?
When we talk about our “metabolisms” in general terms, we’re usually referring to what is known as basal metabolic rate (BMR), or the amount of calories that our bodies need to stay alive. Everyone’s BMR is different. It’s determined by genetics, gender, height, weight, muscle mass and age, and generally makes up between 60% and 75% of the total calories you burn every day.
Why Do Metabolisms Slow with Age?
It’s true. Metabolisms slow with age, starting when we are around 20 years old. At first, the metabolic decrease is barely noticeable. On average, the BMR decrease between age 20 and 30 is between 1 and 2 percent. On average, that means you need to eat 150 fewer calories every day at age 30 to weigh the same amount as you did at age 20, assuming you get in an identical amount of physical activity.
It’s later in life, however, that the drop in BMR becomes precipitous. Starting around age 40 for men and age 50 for women, BMR starts to decline more rapidly. As your body moves away from the “growing” phase and into an “aging” phase, it produces less growth hormone, in turn decreasing your BMR. Other hormones also influence the decline in BMR, including those produced by the thyroid as well as testosterone and estrogen.
There is one other important driver of metabolic slowing: loss of muscle mass. As we age, the average person loses around 3% to 5% muscle mass per decade. This loss of muscle mass become a huge driver of metabolic slowing, because muscle, unlike fat, burns calories even at rest.
Unless you are cutting calories as you get older, this decline in BMR means that you will gain weight.
What You Can Do
You can’t really control the fluctuating hormone levels, so you should focus on what you can influence: your muscle mass.
Muscles are calorie furnaces. Building muscle boosts your BMR, meaning you burn more calories while doing nothing. Building up muscle mass is the best way to increase—or at least maintain—your BMR.
There are two components to building muscle mass. The first is through strength training, which specifically targets muscle building. People who do regular strength training lose less muscle mass as they age, and a Harvard study of 10,500 men showed that strength training was better than aerobic exercise at reducing abdominal fat increase.
Strength training alone is not enough to maximize muscle mass, however. If you want to focus on building muscle, you also need to eat plenty of protein. While the minimum daily protein recommendation is 1 gram of protein per kilogram of body weight, individual needs vary. Some research has shown that, to prevent age-related muscle loss, older adults should consider eating twice the standard recommendation. If you have had weight loss surgery your needs will be greater and will depend on the type of surgery. You will need to discuss this with your surgeon, however; it is likely to be 2 or even 3 times the standard minimum recommendation.
Join the Center for Weight Loss Surgery in a Healthy Lifestyle this Summer
The Center for Weight Loss Surgery can help you discover a healthier lifestyle outdoors. We assist clients in Seattle, the Eastside, and surrounding areas of Washington with maintaining their fitness and eating goals after weight loss surgery. We invite you to attend one of our free informational seminars to explore the different surgeries available. Please call us today at 253-815-7774, toll free 877-815-7774, or complete our online form, to arrange your consultation!