For decades, a common belief has been that metabolism slows with age, leading to unwanted weight gain. It is true about the unwanted weight gain. A 2013 study by the Agency for Healthcare Research and Quality showed an average of 1-2 pounds per year of extra weight between 40-59 years, which adds up to significant weight gain over time. However, don’t be so quick to blame this on “slowing metabolism.”
New Findings on Metabolism Over the LifeSpan
A paper published this past August in the peer-reviewed journal, Science, shows that metabolism—our body’s ability to convert food into energy—stays relatively steady between ages 20 and 60, with some minor declines after that (1). This steady state appears to be as true for women as for men, including women who are going through menopause. This study, which included 6500 participants age 8 days to 95 years, shows metabolism changes over four distinct life stages.
The Real Reason for Unwanted Weight Gain
The real reason we start to gain weight as we get older isn’t because our metabolism starts to slow—it is because we start to slow. If we become more sedentary but continue to eat the same amount of food, there is an imbalance in the energy equation, and we begin to add pounds. In addition, we might continue a walking program but skip the strength training from earlier years. Strength training helps us retain lean muscle mass, which uses more calories than fat in a resting state.
Actions to Take
The tips below not only help avoid unwanted weight gain, but are good for overall heath.
#1. Move more throughout the day. While it is great to “exercise,” more of our calorie burn comes from daily activity than from an hour in the gym. Look for ways to be inefficient in your movement so you need to stand every hour to water some plants or rotate laundry, or take a phone call while walking around in your backyard.
#2. Add strength training to your exercise routine. The American Heart Association recommends training with light weights, resistance bands, or even your own body weight at least twice per week for 30 minutes. If carving out this amount of time is difficult, consider an“exercise snack,” such as some simple arm exercises one day, and legs or core on another. If you’re not sure where to start, try these CDC strength training guidelines for older adults.
#3. Get enough sleep. The National Sleep Foundation recommends 7-9 hours of sleep per night for adults 18-64, and 7-8 hours of sleep beginning at age 65. Yet a third of Americans don’t get the recommended amount of nightly sleep which can lead to metabolic disorders, cardiovascular implications, immune system dysfunction, and the build-up of abnormal proteins associated with Alzheimer’s disease.
Top Takeaway
To learn more about metabolism, check out Burn: New Research Blows the Lid Off How We Really Burn Calories, Lose Weight, and Stay Healthy. It was written by Herman Pontzer, Ph.D., the principle investigator for the recently published study in Science.