You can’t blame midlife weight gain on a slower metabolism, study found
Something surprising happened on my last birthday.
It was Aug. 13 when Science published an article on metabolism. The surprises included not only 80 collaborators but also data that is having us rethink what we thought about metabolism.
That many collaborators provide substantial data and power to a study. This research included 6,400 people from 29 countries ranging in age from 8 days to 95 year old. They studied energy expenditure only (calorie burning) — not food intake or hormone changes.
The researchers identified four phases of changes in energy expenditure during the lifespan.
Phase 1- Birth to age 1
At one month of age, an infant starts to have incredible energy requirements to support growth.
Phase 2- Age 1-20
During this phase, metabolic rate continues to increase proportional to the amount of fat free mass a person has.
Phase 3- Age 20-60
Yes, you are reading that correctly. Metabolism does not come to a screeching halt at 40 or menopause or even after pregnancies. It is fairly stable until around age 60.
Phase 4 - Age 60 and beyond
At this phase, researchers identified a decline in metabolism of about 0.7% a year. Another interesting point is that organ specific energy expenditure, particularly the brain and liver, is elevated in juveniles and reduced in older adults.
This data is particularly important for researchers looking at disease origins and medical and pharmaceutical treatments. There are also pearls for the public.
If you are noticing weight gain around midlife or midsection, don’t blame your metabolism. Look at your lifestyle. With work and family, perhaps sedentary time has increased and active time decreased.
According to government physical activity guidelines, adults should engage in moderate intensity level exercise for 2.5 to 5 hours a week. They state, “Additional health benefits are gained by engaging in physical activity beyond 5 hours a week.”
Wearable activity trackers are great for learning how much you move and motivating for more.
Sheah Rarback MS, RDN is a registered dietitian nutritionist in private practice in Miami. srarback@hotmail.com