Does metabolism actually slow down with age?

You may be familiar with metabolism as it relates to your body’s ability to gain and lose weight. While this is true, it only tells part of the story.  

Your metabolism encompasses all the biochemical reactions in the body, and one of these key roles is converting food and drinks into energy. Your body uses this energy for vital functions such as breathing, brain power, digestion, repairing muscle, and much more.¹ 
 
Metabolic rate — the rate at which your body burns calories to keep going — is unique to every person, and is determined by genetics, age, muscle mass, and activity level. Increasing your metabolic rate is commonly referred to as “boosting metabolism.”  

Having a fast metabolism means your body burns more calories, while someone with a slower metabolism needs fewer calories and does not convert food into energy as efficiently. 

So, does metabolism slow down with age? The answer is yes — but not as drastically as you may think.  

Strength training supports muscle tissue, which helps your body process glucose and keeps your metabolism running efficiently.

Does metabolism slow down with age? What the research says 

Yes, research shows that metabolism does slow down with age. People may assume it’s a gradual decline after young adulthood, but studies have found that your metabolism doesn’t significantly slow down until later in life.   

From the age of about 20 to 60, most people's metabolic rates remain pretty consistent, according to a study published in Science. This research found that metabolic rate starts to decrease after age 60, by about 0.7 percent each year.² 
 
A slow metabolism is often blamed for weight gain later in life. While science confirms this is a factor, there may be other reasons for gaining weight as you get older, including decreased activity, loss of muscle mass, diet changes, and how we respond to the food we’re eating.^2,3 

Why your metabolism slows down with age 

Muscle loss is one of the many reasons why your metabolism slows with age. Muscle mass decreases 3-8% per decade after age 30, and after age 60, the rate of decline goes even higher.³   

As adults age, natural reductions in hormones such as testosterone and oestrogen lead to muscle loss, which has a negative impact on your metabolism. Muscle tissue burns more calories at rest than body fat,³ and the more muscle you have, the more efficiently your body processes glucose.⁴ 

Another hormone, insulin, plays a role in turning on muscle protein synthesis (creation of new muscle tissue), and limits breakdown of muscle. Insulin resistance is more common in older individuals, and it’s partially responsible for age-related muscle loss and the accompanying metabolic changes.³  

Insulin also regulates glucose, so maintaining balanced glucose levels can also play a role in having a healthy metabolism.⁵ Using Lingo, which is a continuous glucose monitor (CGM), can help you gain insights into your unique glucose responses and support metabolic health as you age. 

As you get older, you may also become less active, which can lead to losing muscle mass and gaining body fat. Not only do you burn fewer calories with less movement, but the loss of muscle further decreases energy expenditure.⁶   

Another cause: As you age, your body needs fewer calories to function.² Shifts in nutrition habits may come with age as well, such as eating alone, difficulty cooking or feeding yourself, decreased appetite, or decreased access to healthy food^6,7 — all of which can impact your weight.   

Muscle loss is one of the many reasons why your metabolism slows with age. Muscle decreases 3-8% per decade after age 30. After age 60, it’s even higher.³   

It's possible to support metabolism as you age with some lifestyle interventions like strength training and eating enough protein.

How to prevent a slowing metabolism 

While muscle mass and hormonal changes (including insulin resistance) are some of the main drivers of metabolic changes as you age, it's possible to prevent a slower metabolism with some lifestyle interventions:  

1. Eat enough protein: Older adults often struggle to meet their dietary protein needs, which is necessary to support healthy muscles.^3,6 Lingo recommends eating about 1.5 g of protein per kilogram of desired body weight (if your goal weight is 68 kilograms, that’s 102 g of protein a day). Eating enough high-quality protein can benefit your glucose levels, insulin sensitivity, and supports healthy muscle tissue.^8,9 Aim for around 25-35 g per meal.  
    

2. Strength train regularly: Strength training also supports muscle tissue, which helps your body process glucose and keeps your metabolism running efficiently. Since many older adults lose muscle mass as they age, this group should do muscle strengthening activities 2 or more days per week along with 150 minutes of moderate intensity exercise.¹⁰ If time or energy is limited, focus on strength training and balance exercises to give you the most benefit.¹¹
    

3. Maintain steady glucose: As we age, our bodies’ ability to respond to insulin is impaired.³ Focusing on foods that keep glucose levels steady (and thus don't require large amounts of insulin) can help, like low-GI foods. Aim for meals with a quality source of protein, non-starchy vegetables, and healthy fats. When eating carbs, be mindful of portion sizes and choose complex carbs like starchy vegetables or whole grains, eaten alongside or after a source of protein. 

A final note from Lingo 

While metabolism does slow down as you age, it’s often later in life than many people expect. A slowing metabolism may impact weight changes as you get older, but other factors like decreased activity, changes in appetite, loss of muscle mass, and dietary changes can also contribute. 

Using Lingo can help you understand your habits and patterns and work towards limiting glucose (and insulin) spikes, which can help mitigate the metabolic changes seen with ageing.   

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