Does Your Metabolism Really Slow Down as You Get Older?
What Really Happens to Your Metabolism After 50—and What You Can Do About It
HEALTH
Coach Marcus Jones
8/2/202614 min read
Have you ever heard somebody over 50 say:
“I used to be able to eat whatever I wanted. Now I just LOOK at food and gain weight!”
I hear it all the time.
And maybe you've said it yourself.
You hit your 40s or 50s, your waistline starts changing, losing weight doesn't seem as easy as it once was, and immediately we blame one thing:
OUR METABOLISM.
“My metabolism is slow.”
“My metabolism crashed after 50.”
“My metabolism isn't what it used to be.”
But is that really what's happening?
The answer is:
YES—AND NO.
Your body's energy needs can change as you age.
But the idea that your metabolism suddenly falls off a cliff the moment you hit 40, 50, or even 60 is too simple.
In fact, some of the best research we have on human energy expenditure tells a much more interesting story.
So let's break it down.
QUICK ANSWER: DOES METABOLISM REALLY SLOW DOWN AFTER 50?
Not necessarily in the dramatic way many people assume.
A major 2021 study published in Science examined daily energy expenditure across the human lifespan and found that, after adjusting for differences in body size and composition, energy expenditure was relatively stable from approximately:
AGE 20 THROUGH AGE 60
[Source 1]
After about age 60, adjusted energy expenditure began declining gradually.
That means turning 40 or 50 doesn't automatically trigger a metabolic collapse.
However, body weight and body composition can still change in midlife because of factors including:
Reduced physical activity
Loss of muscle
Changes in eating habits
Sleep
Hormonal changes
Medications
Health conditions
Changes in lifestyle
Overall calorie intake
The National Institute on Aging also notes that metabolism can change with age and that some older adults may need to become more active or consume fewer calories to maintain their weight.
[Source 2]
So the better question isn't simply:
“Did my metabolism slow down?”
The better question is:
“WHAT ELSE HAS CHANGED IN MY LIFE?”
FIRST—WHAT IS METABOLISM?
People talk about metabolism constantly, but what does the word actually mean?
Metabolism refers broadly to the chemical processes your body uses to sustain life.
Your body needs energy to:
Keep your heart beating
Breathe
Maintain body temperature
Support brain function
Repair tissues
Digest food
Move
Exercise
Perform everyday activities
The energy we get from food and beverages is measured in:
CALORIES.
Your body uses calories throughout the day, whether you're exercising or sleeping.
When we talk about how many calories your body uses, we're talking about different components of energy expenditure.
YOUR METABOLISM IS MORE THAN WHAT HAPPENS AT THE GYM
Your total daily energy expenditure comes from several areas.
RESTING ENERGY EXPENDITURE
This is the energy your body uses simply to stay alive.
Even if you stayed in bed all day, your body would still need energy to:
Breathe.
Circulate blood.
Run your brain.
Maintain your organs.
Control your body temperature.
PHYSICAL ACTIVITY
This includes intentional exercise such as:
Walking
Running
Cycling
Strength training
Swimming
But it also includes everyday movement.
THE THERMIC EFFECT OF FOOD
Your body uses energy to digest, absorb, and process the foods you eat.
All of these contribute to your daily calorie expenditure.
So metabolism isn't simply:
“How many calories did I burn on the treadmill?”
It's happening:
24 HOURS A DAY.
ONE OF THE BIGGEST METABOLISM STUDIES CHANGED THE CONVERSATION
For years, many people assumed metabolism began declining steadily during adulthood.
Then researchers looked at a much larger dataset.
A 2021 study published in Science analyzed measurements from more than:
6,400 PEOPLE
ranging in age from infancy to 95 years old.
[Source 1]
Researchers used a highly regarded method called doubly labeled water to measure total daily energy expenditure.
After accounting for body size and composition, the researchers found four broad stages of energy expenditure across life.
STAGE 1: INFANCY
Energy expenditure rises rapidly during infancy.
Babies have extremely high metabolic demands relative to their body size.
STAGE 2: CHILDHOOD AND ADOLESCENCE
Energy expenditure gradually declines from its infant peak toward adult levels.
STAGE 3: ADULTHOOD
Here's the part that surprised a lot of people.
From approximately:
AGE 20 TO AGE 60
adjusted total energy expenditure was relatively stable.
[Source 1]
Read that again.
Your metabolism doesn't necessarily start collapsing at 30.
Or 40.
Or 50.
That doesn't mean your BODY doesn't change during those decades.
It means metabolism alone may not explain all the weight gain people experience in middle age.
STAGE 4: AFTER ABOUT AGE 60
After approximately age 60, energy expenditure began to decline gradually.
Researchers estimated a decline of roughly:
0.7% PER YEAR
after age 60.
[Source 1]
That doesn't mean everybody experiences exactly the same decline.
We are individuals.
But the study challenges the common belief that metabolism starts dramatically slowing during middle age.
SO WHY DOES WEIGHT GAIN FEEL SO MUCH EASIER AFTER 50?
Now we're getting to the real conversation.
Because even if metabolism remains relatively stable through much of adulthood, other things may NOT remain stable.
Think about your life at 25.
Maybe you:
Played sports
Walked more
Went out dancing
Had a physically demanding job
Were constantly moving
Had young children keeping you busy
Spent less time sitting
Ate smaller portions
Didn't snack as often
Slept differently
Now compare that with life at 50.
You may have:
A desk job
More driving
More sitting
Less recreational activity
Less muscle
More stress
Different sleep patterns
Different eating habits
More restaurant meals
More medications
Different health conditions
That's a lot of change!
Yet we often blame everything on:
“MY METABOLISM.”
Sometimes the bigger issue is that our lifestyle changed while our eating habits didn't.
YOU MAY SIMPLY BE MOVING LESS
This is one of the biggest things people underestimate.
You don't have to completely stop exercising to experience a reduction in daily movement.
Maybe you still go to the gym three times a week.
Great.
But what are you doing during the OTHER 165 hours of the week?
Are you sitting?
Driving?
Watching television?
Working at a computer?
Scrolling on your phone?
Physical activity isn't only formal exercise.
Everyday movement contributes to how much energy you use.
The National Institute of Diabetes and Digestive and Kidney Diseases notes that older adults may use fewer calories, especially if they become less physically active.
[Source 3]
That's why one of my favorite healthy-aging messages is:
MOVE MORE THROUGHOUT THE DAY.
Not just at the gym.
MUSCLE MATTERS
If you've followed Week 1 of this series, you knew this was coming.
We're talking about muscle again.
As adults get older, they may lose muscle, particularly if they aren't physically active.
[Sources 2 and 3]
Muscle is metabolically active tissue.
Your body composition therefore influences your energy needs.
But I want to be careful here.
You may hear fitness influencers say:
“Build muscle and your metabolism will skyrocket!”
That's exaggerated.
Adding muscle doesn't magically turn your body into a calorie-burning furnace.
However, preserving muscle remains extremely important for:
Strength
Physical function
Mobility
Independence
Body composition
Healthy aging
And resistance training can help maintain muscle as we get older.
So the goal isn't:
BUILD MUSCLE JUST TO BURN CALORIES.
The bigger goal is:
BUILD AND MAINTAIN MUSCLE SO YOU CAN LIVE STRONGER.
THIS IS WHY STRENGTH TRAINING MATTERS
Last week we talked extensively about strength training.
Now you can see how the pieces connect.
If aging and inactivity are associated with losing muscle, one logical strategy is to give your muscles a reason to stay.
That means:
RESISTANCE TRAINING.
Depending on your ability, that might include:
Dumbbells
Machines
Resistance bands
Body-weight exercises
Cable exercises
Other appropriate resistance training
Federal physical-activity guidance recommends muscle-strengthening activity involving the major muscle groups on at least:
2 DAYS PER WEEK.
[Source 3]
Again:
We're not training simply to look muscular.
We're training to maintain function.
YOUR FOOD INTAKE MAY NOT HAVE ADJUSTED TO YOUR LIFESTYLE
Here's another uncomfortable truth.
Sometimes we're eating like we're still 25...
while moving like we're 55.
That's a problem.
Maybe you used to play basketball three nights per week.
Now you're watching basketball three nights per week.
Same appetite.
Different activity.
The National Institute on Aging explains that weight is influenced by the relationship between the energy we consume through food and beverages and the energy our bodies use.
[Source 2]
That doesn't mean weight management is always simple.
It's not.
Genetics, medications, sleep, hormones, medical conditions, environment, and many other factors matter.
But energy balance still matters too.
WATCH PORTION CREEP
Portions can gradually increase without us noticing.
A little more cereal.
A larger plate.
A second serving.
A bigger restaurant meal.
A snack while watching television.
Another handful of nuts.
A fancy coffee drink.
Those things add up.
You don't have to obsessively count every calorie for the rest of your life.
But you should have some awareness of:
HOW MUCH YOU'RE EATING.
A healthy food isn't calorie-free because it's healthy.
Nuts are nutritious.
Olive oil can fit into a healthy diet.
Avocados are nutritious.
But portions still matter.
LIQUID CALORIES CAN SNEAK UP ON YOU
Some of the easiest calories to consume are the ones we drink.
Think about:
Soda
Sweet tea
Alcohol
Juice
Specialty coffee drinks
Energy drinks
Large smoothies
A person might say:
“Coach, I barely eat anything!”
Meanwhile they're drinking hundreds of calories per day.
Your body doesn't ignore calories just because you didn't chew them.
Water should play a major role in hydration for most people unless a healthcare professional has given different instructions.
SLEEP CAN AFFECT THE WEIGHT-MANAGEMENT PICTURE
Sleep deserves more attention than it gets.
The National Institute on Aging lists sleep as one of the many factors that can influence body weight.
[Source 2]
And think practically.
After a poor night's sleep, are you more likely to:
Prepare a healthy breakfast?
Or grab whatever is convenient?
Exercise?
Or skip your workout?
Take a walk?
Or sit on the couch?
Make thoughtful food decisions?
Or crave something quick?
Healthy habits influence each other.
That's why I don't believe in treating weight management as one isolated behavior.
YOUR WHOLE LIFESTYLE MATTERS.
STRESS CAN CHANGE YOUR HABITS TOO
Stress doesn't magically create calories.
But stress can absolutely influence behavior.
Some people eat when they're stressed.
Some drink more alcohol.
Some stop exercising.
Some sleep poorly.
Some grab fast food because they don't feel like cooking.
Some people experience the opposite and lose their appetite.
We're all different.
But if you're trying to understand changes in your weight after 50, don't only ask:
“What's wrong with my metabolism?”
Ask:
“WHAT HAS HAPPENED TO MY LIFESTYLE?”
That's often where useful answers begin.
HORMONES CAN MATTER—BUT DON'T BLAME EVERYTHING ON HORMONES
Midlife also comes with hormonal changes.
For women, the menopause transition can affect body composition and where body fat is stored.
For men, hormonal levels can change with aging too.
But here's what I don't want people doing:
Self-diagnosing a hormonal disorder because they gained 10 pounds.
Hormones are complicated.
If you are experiencing symptoms that concern you—including unexplained weight changes, severe fatigue, temperature intolerance, significant changes in sleep, or other symptoms—talk with your healthcare professional.
Conditions involving the thyroid and other systems can influence weight and energy.
GET TESTED WHEN APPROPRIATE.
Don't diagnose yourself from social media.
MEDICATIONS CAN SOMETIMES AFFECT WEIGHT
Another factor people don't always consider:
MEDICATION.
Some medications can influence:
Appetite
Fluid retention
Energy
Physical activity
Body weight
If you notice a significant change in your weight after beginning a medication, talk with your healthcare professional.
Don't stop taking prescribed medication on your own.
Your doctor can help determine whether the medication could be contributing and whether alternatives are appropriate.
DON'T USE AGE AS AN EXCUSE
Here's where Coach Marcus has to give you some straight talk.
There's a difference between acknowledging that aging changes your body...
and using age as an excuse for every habit you don't want to change.
Sometimes it's easier to say:
“I'm getting old.”
than:
“I'm not moving enough.”
Sometimes it's easier to say:
“My metabolism is slow.”
than:
“My portions have gotten too big.”
Sometimes it's easier to say:
“It's hormones.”
than:
“I'm sleeping five hours a night and eating fast food four times a week.”
We need honesty.
Not shame.
HONESTY.
Because you can't change what you won't acknowledge.
THE GOOD NEWS: YOU STILL HAVE LEVERS YOU CAN PULL
This is the part I want you to remember.
Even if metabolism changes as you age, you are NOT powerless.
You can influence:
YOUR MOVEMENT.
Walk.
Exercise.
Take the stairs when appropriate.
Stand more.
Stay active.
YOU CAN INFLUENCE YOUR MUSCLE
Strength train.
Challenge your muscles.
Eat adequate protein for your individual needs.
Recover.
Stay consistent.
YOU CAN INFLUENCE YOUR FOOD CHOICES
Focus more often on nutrient-dense foods such as:
Vegetables
Fruits
Whole grains
Lean proteins
Beans and lentils
Nuts and seeds
Other foods appropriate for your health needs
[Source 4]
You don't need perfection.
You need a pattern you can maintain.
YOU CAN INFLUENCE YOUR PORTIONS
Pay attention to how much you're eating.
Especially restaurant meals.
Especially highly processed snacks.
Especially foods that are easy to over-consume.
YOU CAN INFLUENCE YOUR SLEEP
Develop a consistent sleep routine.
Create an environment that supports sleep.
Talk with your healthcare professional if sleep problems persist.
YOU CAN INFLUENCE YOUR CONSISTENCY
This may be the biggest one.
One healthy meal won't change your life.
One workout won't change your life.
One walk won't change your life.
But what happens when you repeat those actions:
FOR YEARS?
That's where things get interesting.
STOP TRYING TO “BOOST” YOUR METABOLISM WITH MIRACLE PRODUCTS
Everywhere you look, somebody is selling:
“Metabolism boosters!”
“Fat burners!”
“Thermogenic miracle formulas!”
“Drink this and melt fat!”
Come on now.
There is no supplement that replaces the fundamentals.
And supplements marketed for weight loss or metabolic enhancement may have risks, interactions, or ingredients that aren't appropriate for everyone.
Don't assume:
“NATURAL” = “SAFE.”
Discuss supplements with a qualified healthcare professional, particularly if you take medication or have medical conditions.
YOU DON'T NEED TO STARVE YOURSELF
Another reaction people have when weight becomes harder to manage is:
“I'll just stop eating!”
That's not a healthy long-term strategy.
Especially as we get older and preserving muscle becomes increasingly important.
The goal isn't:
EAT AS LITTLE AS POSSIBLE.
The goal is:
EAT APPROPRIATELY FOR YOUR BODY AND GOALS.
That means considering:
Calories
Protein
Nutrient quality
Fiber
Fruits and vegetables
Hydration
Medical needs
Activity
Sustainability
Healthy weight management should support your health—not punish your body.
DON'T BECOME OBSESSED WITH THE SCALE
You know what I care about more than simply seeing a lower number?
BODY COMPOSITION.
STRENGTH.
FITNESS.
HEALTH.
The National Institute on Aging points out that the number on the scale and even BMI don't tell the entire story in older adults.
An older person at a “normal” weight can have less muscle and more body fat than someone who weighs slightly more.
[Source 2]
That's why I want you asking:
How strong am I?
How active am I?
How does my waistline look?
How do my clothes fit?
What is my blood pressure?
What is my blood glucose?
How are my cholesterol levels?
How do I feel?
HEALTH IS BIGGER THAN A SCALE.
A SIMPLE COACH MARCUS METABOLISM STRATEGY AFTER 50
Let's make everything practical.
1. MOVE EVERY DAY
Don't allow inactivity to become your normal.
2. STRENGTH TRAIN
Preserve and build muscle appropriate for your age, health, and abilities.
3. GET YOUR CARDIO
Work toward appropriate aerobic-activity recommendations.
4. EAT WITH PURPOSE
Prioritize nutrient-dense foods most of the time.
5. GET ADEQUATE PROTEIN
We covered this during Week 1, Day 3. Your individual needs vary.
6. WATCH PORTIONS
Healthy foods still have calories.
7. WATCH LIQUID CALORIES
Don't drink your entire calorie budget.
8. PRIORITIZE SLEEP
Recovery matters.
9. KNOW YOUR HEALTH NUMBERS
Pay attention to appropriate health screenings and laboratory values.
10. STAY CONSISTENT
Your body responds to what you repeatedly do.
WHAT IF YOU'RE DOING EVERYTHING RIGHT AND STILL GAINING WEIGHT?
This is important.
Don't automatically assume you lack discipline.
If you're experiencing:
Unexplained weight gain
Unexplained weight loss
Severe fatigue
Swelling
Significant appetite changes
New weakness
Persistent digestive problems
Other concerning symptoms
Talk with your healthcare professional.
There may be medical factors that deserve evaluation.
Your healthcare professional can also review medications, medical history, dietary habits, physical activity, and laboratory testing when appropriate.
DON'T GUESS WHEN YOUR HEALTH IS INVOLVED.
MY 6 METABOLISM RULES AFTER 50
If you remember nothing else from today's article, remember these:
1. YOUR METABOLISM DOESN'T AUTOMATICALLY CRASH AT 50
Research suggests adjusted energy expenditure is remarkably stable through much of adulthood.
2. YOUR LIFESTYLE MAY HAVE CHANGED MORE THAN YOUR METABOLISM
Look honestly at your movement, eating, sleep, and habits.
3. PROTECT YOUR MUSCLE
Strength training becomes increasingly important.
4. KEEP MOVING
Daily activity matters—not only formal workouts.
5. EAT FOR THE BODY YOU HAVE TODAY
Your needs at 55 may not be identical to your needs at 25.
6. STOP LOOKING FOR METABOLIC SHORTCUTS
Consistency beats gimmicks.
MAYBE YOUR METABOLISM ISN'T THE ENEMY
This is what I want you to take away today.
Maybe you've spent years saying:
“My metabolism is terrible.”
Maybe you've convinced yourself there's nothing you can do because you're getting older.
I want you to reconsider that story.
Yes, aging matters.
Yes, your body changes.
Yes, your energy needs can change.
And yes, after about age 60, research suggests metabolic energy expenditure does gradually decline.
But that doesn't mean your health is predetermined.
YOU STILL HAVE A LOT OF INFLUENCE.
You can move.
You can strength train.
You can eat with purpose.
You can sleep.
You can manage your portions.
You can build healthier routines.
You can work with your healthcare team.
You can keep learning.
You can stay consistent.
And you can stop blaming your 50th birthday for everything.
Your body has changed.
So let's adapt.
Not complain.
Not quit.
ADAPT.
That's what healthy aging is about.
We're not trying to become 25 again.
We're learning how to become the healthiest, strongest version of who we are TODAY.
And remember:
DON'T JUST GET OLDER. GET BETTER AT IT.
Faith. Health. Wealth. Build All Three.
— Coach Marcus Jones
Medical, Fitness & Nutrition Disclaimer
This article is provided for general educational and informational purposes only. It is not intended to diagnose, treat, cure, or prevent any disease or medical condition and should not be considered medical advice, nutritional counseling, an individualized weight-management plan, or an exercise prescription. Metabolism, energy requirements, body composition, and body weight vary based on age, sex, genetics, medical history, medications, hormone status, sleep, activity level, nutritional intake, and other individual factors. Consult your physician, registered dietitian, or another qualified healthcare professional before beginning or substantially changing a nutrition, weight-loss, supplement, exercise, or wellness program—particularly if you have diabetes, cardiovascular disease, kidney disease, thyroid or other endocrine conditions, a history of eating disorders, take prescription medication, or have other medical concerns. Do not discontinue or alter prescribed medication based on information in this article. Seek professional evaluation for unexplained or concerning weight changes, fatigue, weakness, swelling, or other persistent symptoms. Never disregard professional medical advice or delay seeking medical care because of information contained in this article.
Source Annotations & Further Reading
[Source 1] Pontzer H, Yamada Y, Sagayama H, et al. Daily Energy Expenditure Through the Human Life Course. Science. 2021;373(6556):808–812. PMID: 34385400.
Researchers analyzed daily energy expenditure across a dataset of more than 6,400 people ranging from infancy to age 95. After adjusting for body size and composition, energy expenditure was relatively stable from approximately age 20 through 60, followed by a gradual decline later in life. This study challenges the common assumption that metabolism automatically begins falling sharply in early or middle adulthood.
[Source 2] National Institute on Aging — Maintaining a Healthy Weight. National Institutes of Health.
The National Institute on Aging explains that weight is influenced by many factors, including age, genetics, sex, lifestyle, family habits, culture, sleep, and environment. NIA notes that metabolism can change with age and that some older adults may need to become more active or adjust calorie intake to maintain a healthy weight. NIA also emphasizes that body weight and BMI alone do not provide a complete picture of health in older adults.
[Source 3] National Institute of Diabetes and Digestive and Kidney Diseases — Health Tips for Older Adults. National Institutes of Health.
NIDDK explains that older adults may use fewer calories, particularly when they are less physically active. The agency encourages regular aerobic activity and muscle-strengthening activity and notes that strength training can help maintain muscle as people age or lose weight. General recommendations include at least 150 minutes of moderate-intensity aerobic activity per week and muscle-strengthening activity at least two days per week.
[Source 4] National Institute of Diabetes and Digestive and Kidney Diseases — Eating & Physical Activity to Lose or Maintain Weight. National Institutes of Health.
NIDDK recommends a sustainable healthy eating pattern emphasizing vegetables, fruits, whole grains, appropriate dairy or alternatives, and protein sources such as lean meats, poultry, eggs, seafood, beans, lentils, nuts, seeds, and soy foods. The agency also emphasizes regular physical activity as an important component of long-term weight management.
[Source 5] National Institute of Diabetes and Digestive and Kidney Diseases — Am I at a Healthy Weight? National Institutes of Health.
NIDDK notes that older adults tend to lose muscle and bone and gain body fat with age. The agency emphasizes that body-fat distribution matters and that excess abdominal fat may be associated with greater health risk even when overall BMI does not change substantially.
Week 2 — Metabolism, Energy & Weight
Day 1: Does Your Metabolism Really Slow Down as You Get Older?
Day 2: Why Do You Feel More Tired as You Get Older?
Day 3: What Is the Best Time of Day to Exercise?
Day 4: Is Walking Enough Exercise After 50?
Day 5: How Many Steps Should Adults Over 50 Get Each Day?
Day 6: What Is the Fat-Burning Heart Rate Zone?
Day 7: Why Is Maintaining Muscle Important for Your Metabolism?
Coach Marcus Jones 90-Day Faith, Health & Wealth Series, Week 2 — Metabolism, Energy & Weight, Day 1 — Does Your Metabolism Really Slow Down as You Get Older?