Talking wistfully about your younger days—when it seemed like you didn’t gain an ounce, no matter how much you ate and how little you exercised—is something many of us do as we age. And we often do it with a chuckle, a shake of the head, and regret for not appreciating our high metabolism at the time.

But a recently published study in the research journal Science—involving more than 6,400 people from 29 countries, ages 8 days to 95 years—rebuts that conventional metabolism wisdom.

What we know now about metabolism

“We always assumed that metabolism may slow down after age 40, especially in women, due to changes associated with menopause and perimenopause,” notes Dr. Mary Carroll, an endocrinologist at Summit Health. “The data from this study suggests metabolism is very high in early childhood, declines slowly to adult levels by age 20, remains stable between ages 20 and 60, and declines steadily after age 60.” The study also revealed that there are no significant differences between the metabolic rates of women and men after controlling for other factors.

In short, that means there is no difference between a 20-something and a 40-something when it comes to metabolism. Yes, your metabolism does eventually slow down, but not until age 60. “However,” reminds Dr. Carroll, “muscle mass declines in adulthood, especially in women, so that is something to be cognizant of.”

What this means for health care approaches

Many in the medical community agree that this study could shift the science of human physiology. It highlights the critical importance of infant nutrition due to the increasing energy demands of growing babies. The study also impacts such things as determining the right drug doses for children and older people.

But what it doesn’t do is change how people should approach their personal health. “This study only helps us to tell our patients that they need to focus on long-term healthy lifestyle changes via diet and exercise to meet their goals,” says Dr. Carroll, pointing to the fact that weight loss and obesity are complex and go far beyond metabolism.

How to take control of your weight loss

If you are concerned about meeting your weight loss goals, speak with your doctor, who can evaluate you for secondary causes for weight gain or difficulty with weight loss via nutrition analysis, evaluation for underlying mood or eating disorders, and hormonal causes.

Don’t look for quick fixes, Dr. Carroll warns. “The new study shows that if you exercise regularly to maintain muscle mass, you can continue to use calories just as efficiently at age 60 as you did at age 20, and if you add muscle, you can boost your metabolism.” When it comes to physical activity, keep the mindset of sustainability. Find an activity or sport you enjoy doing so that exercise isn’t a chore. Weight training and cardio are both necessary parts of a fitness routine, especially as you grow older.

Many doctors also warn against fads such as extreme low-carb, high-fat diets. Focusing on a diet that emphasizes vegetables, fruits, whole grains, and lean meats is much more sustainable.

If there’s one key thing to learn from the results of this study, it’s that leading an active, nutritionally balanced lifestyle throughout your life is the most important step to take when it comes to maintaining a healthy weight.

At Summit Health, many clinics have DXA scanners, which in addition to measuring bone density, can be used to accurately measure body composition, body fat, and muscle mass.