They say it’s unavoidable, but “they” might be wrong. Great news for those of us over 40!
They say metabolism slows down after 40 and that’s why you’re gaining weight.
But what if they are wrong?
Let’s talk about some new information about metabolism and age.
Metabolism is the process through which your body converts food into energy.
Even when you’re at rest, you need some energy to aid in breathing, repairing cells, organ function – just being alive.
The calories that your body needs for this are called BMR, Basal Metabolic Rate.
If you wear a gadget that shows your 24 hour calorie burn, you’ll notice that most of the calories burned each day are not what you burned exercising.
Even on a day where you don’t move around very much, you burned quite a bit.
A big chunk of that is your calculated BMR.
Our total calorie burn for a day is roughly 70% BMR, 20% extra activity, and 10% of our energy is used to digest food.
You’ve probably heard that when you hit 40, your metabolism will slow down causing you to gain weight.
Researchers have been looking at this for a while and it’s not true.
And the news for those of us who are over 40 is encouraging!
The study I’m talking about right now was published in August of 2021 on Science.org.
It’s called Daily Expenditure Through the Human Life Course.
They looked at over 6000 subjects, 64% of them are female, and all ages from newborn up through people in their 90s.
And what they found was that metabolism is very fast for babies, but in adulthood, between the ages of 20 and 60, when you adjust for different body compositions, metabolism stayed stable regardless of gender.
Body composition matters.
People with similar bodyfat to muscle ratios, had similar metabolic rates, but age didn’t seem to matter until people were much older.
They found that metabolism begins to drop after 60, but only slightly.
The most significant change didn’t show up until people were in their 90s.
What did they see happen after the age of 60?
Metabolism declined, but by less than 1% per year.
They calculated it to be 0.7%, to be precise.
Let’s look at an example to put it in perspective.
Consider a woman who is 50 years old, who is 5′ 4″ tall and weighs 170 pounds.
Using an online calculator to estimate her BMR, it would be
When she’s 60, if it slows down by 0.7%, take 1460 times 0.007 and you get 10.22.
That means the part of her metabolism that she can’t control, only slows down by 10 calories per day!
Here’s some 10 calorie foods: three cherry tomatoes, three grapes, half of a cashew, one tortilla chip.
Now granted, online BMR calculators tend to return a higher number than we think is true.
But even if you think your BMR is less, that means when it slows down, it will still only to be slower by 0.7% if the results of this study are a good estimation.
And in real life, many of us know people over 40 who have had success with their fitness goals. (Some of us even did while we were going through menopause.)
Weight gain in midlife is not due to a slower metabolism.
That doesn’t mean something hasn’t changed and that doesn’t mean it’s not a little harder.
What seems to be happening is that as we age, we are less active than we used to be.
It’s not the BMR part that’s changing.
It’s the 20% activity part.
There are many reasons why we’re less active – busy adults with a ton of responsibilities, old injuries or new health problems that make it harder to move. Poor sleep – that can impact weight on its own, but if we don’t sleep well, work all day, we’re just tired.
Regardless of whether we have a slow or a fast metabolic rate, we have to work with what we’ve got.
Don’t get caught up in the weeds – work with the basics.
You have a calorie burn and a calorie intake. If these two are equal, you’ll maintain your current weight.
If you make small adjustments so that your burn is 200 to 500 calories higher each day on average, the body will tap into stored fat to make up the difference.
This takes time. This takes consistency. Takes a little bit of
But keep in mind the science is telling us that our metabolism isn’t what’s adjusting – its us and we can control that.
So work with what you have and you can get to your goals!
And keep in mind the body is designed to adapt, so if you hit a weight loss plateau, watch this video to learn how to bust it.
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Hi! I'm Tammy! I was a busy, stressed, and unhealthy teacher until I decided to take control of my health. I did not become an athlete until I was in my 50's!
I earned personal training and fitness nutrition certifications, then retired from teaching to dedicate my work life to fitness education for other busy women over 40.
My results are obviously not typical because most people don't train to compete as a bodybuilder.
But I believe everyone can make positive changes with healthy habits! Each of us has a unique combination of strengths and challenges that need to be considered to customize a program that will work for us. Science-based principles, flexibility, and consistency make all the difference.