You know your chronological age—the number you tick off each year. But what about your metabolic age? Essentially, metabolic age is how many calories your body burns at rest (or the energy your body needs to maintain its daily functions), and how that compares to other people your age.
While chronological age is based on the number of years you’ve lived—and there’s really nothing you can do to change that number—a few lifestyle tweaks can help adjust your metabolic rate.
Metabolic Age Calculator
What is metabolic age?
It is difficult to determine metabolic age without first determining the basal metabolic rate (or BMR).
“Your basal metabolic rate is the amount of caloric energy, or energy from calories, needed to keep your body functioning, including organs, digestion, muscles, and everything else working during your resting period,” explains functional medicine doctor Heather Modey.
If you were to lie in bed all day, that’s what your body would need to function properly. BMR depends on your gender, height, weight, muscle mass, and a number of other factors. The higher your BMR, the higher your metabolic age.
How to Calculate Your Metabolic Age
To calculate your metabolic age, you need to know your BMR. For that, it’s best to see a health care professional who can give you a more accurate number, says naturopathic physician and functional medicine expert Kara Fitzgerald, ND
However, to get an idea of your metabolic age right now, the most common formula is the Mifflin-St Jeor equation:
- For men: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) + 5
- For women: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) + 5 – 161
What does your metabolic age tell you about your health?
Your metabolic age is influenced by many factors beyond muscle and fat, including hormones and gender, says Modey. Our BMR is typically highest when we’re young, when we’re growing and developing, she says, but then it drops in your 20s and continues to fall after that.
Some studies do show a link between lower BMR and some health outcomes, including age-related mortality and diabetes.
Additionally, your metabolic age is related to your metabolic health, which is a strong indicator of your overall well-being. Markers of metabolic health include things like waist circumference, blood sugar, triglycerides, cholesterol, and blood pressure (you can read more about this here).
However, when it comes to your health, there is a downside to looking at BMR and metabolic age — basically, it’s nearly impossible to compare your personal BMR to others in your age group because so many factors play a role in how many calories you burn. “Rest,” says Modey. Your body type and shape, your ethnicity, your genetics — all of these can play a role.
Robin Foroughton, a spokesperson for the Academy of Nutrition and Dietetics, also talks about things like thyroid health, mitochondrial health, nutrient status, and metabolic flexibility (or how well your body switches from a carb-burning metabolism to a fat/ketone-burning metabolism).
In general, your goal should be to keep your BMR high by living a healthy lifestyle. Modey recommends comparing your personal numbers over time rather than comparing your body (or BMR) to other people.
“When you look at BMR, 70 percent is due to height, weight, and genetics—that leaves about 30 percent of the variables you can control,” she explains. In other words, certain lifestyle choices can positively impact metabolic age.
How to Improve Your Metabolic Age
- Do more activity during the day
- Do strength training
- Add HIIT
- Sleep
- Control your calories
- Fill your plate with healthy foods
- Manage stress
Fitzgerald recently released a small pilot study with her team that found that after an eight-week program that included sleep, nutrition, and exercise components, as well as relaxation techniques and supplements, participants’ biological age dropped by three years, showing that as long as you can, you can influence what’s going on inside.