For many of us, part of that equation may be the fact that our metabolisms slow with age. Here’s what you need to know about metabolism and aging.
What is metabolism?
Metabolism refers to all the chemical reactions our bodies perform to turn the calories we eat and drink into energy. It’s a complex process that includes digestion, breathing, regulating hormones, and so on.
When is your metabolism working?
All the time, to a degree. Our bodies are always burning some calories simply to keep us alive, even when we’re just watching TV or reading.
The number of calories you burn at rest is called your basal metabolic rate (BMR), and genetics, age, gender and hormones all play a role in it. You may find it helpful to know your BMR in order to gauge how many calories you burn a day just by going about your life. Find yours using this online calculator or ask your doctor to calculate it at your next visit.
Why does metabolism slow as you get older?
There are several reasons:
- As we age, our bodies don’t produce as much growth hormone, which is what’s largely responsible for building muscle mass and burning fat
- We often become more inactive as we get older, and
- Most people will experience age-related muscle loss at some point.
What is age-related muscle loss (sarcopenia)?
Until age 30 our muscles grow bigger and stronger. After that, you may start to lose mass and function. While active people will typically stave off most muscle loss until age 75 or so, people who aren’t physically active may see drastic losses early on.
Physically inactive people can lose up to 3-8% of their muscle mass every decade after 30, which leads to decreased strength and mobility. That means a physically inactive person at age 60 may have 24% less muscle mass than they did at age 30, and often that lost muscle is replaced by fat.
Why does muscle mass matter?
Muscle burns more calories than fat all day, every day. It’s high-maintenance tissue, which means your body uses more calories to sustain it than it uses to maintain fat.
When does metabolism start to slow?
While you may have heard people assign a number — 30, 40, 50 — to a drop off in metabolism, it actually happens gradually. So while you may notice yourself gaining weight at 50 even with the same diet you had at 40, it’s more likely that lifestyle changes are to blame than big shifts in your metabolism. For example, most of us are more active at age 25 than 35, and we may have less time or energy for exercise as we get older due to work and family commitments.
The average 50 year-old woman needs 300-500 fewer calories per day than she did in her 20s to maintain the same body weight.
Does metabolism change affect women and men differently?
Yes. Women can expect the biggest metabolism changes close to menopause, when key hormones such as estrogen decrease. For men, the change will be more consistent over time.
What can you do to help your metabolism perform at its best?
- Add resistance or strength training
Lifting weights, doing yoga or working with bands builds muscle strength and increases endurance. Strength training twice a week can have a significant impact.
- Try high-intensity interval training (HIIT)
These workouts alternate between intense exercise and short periods of rest and may boost your metabolism for up to 2 hours afterward.
- Get enough of sleep, whatever that means for you.
Sleep-deprived people can’t regulate blood sugar as effectively, which increases hunger during the day. You may also want to consider turning your thermostat down a few degrees as cooler temperatures foster sleep.
Your metabolism slows while you sleep, but a nutritious, high-protein breakfast can jumpstart it.
- Good fats
People who are concerned about their metabolism often cut fat out of their diets, but that can cause your body to go into starvation mode. “Good fats,” however — avocados, seeds, nuts, fish — can actually boost your metabolism and help ensure you don’t binge later.
- Protein at every meal
Protein keeps you full which helps keep your blood sugar from spiking, and your body has to work hard to break it down, which burns more calories.
- Spicy foods
Studies have found that the capsaicin found in chili peppers can boost your metabolism up to 20% for 30 minutes, and it may help curb your appetite.
- Green tea
Some studies say the caffeine and plant compounds in green tea can boost your metabolism by 4-5%.
You’ve heard it before, but a hydrated body works better, and that includes metabolism.