seniors having a good time together over food

Why Metabolism Decreases with Age and Tips for Improving It

Remember when you were young and could eat almost anything and not have to worry about gaining any weight? With age, however, this becomes a problem.

As you grow old, your body shows noticeable changes, and eating as much as you want without gaining weight isn’t possible anymore.

The simple yet science-backed explanation is this: metabolism decreases with age.

With a weak metabolism, your body slows in its ability to transform calories into energy effectively. Instead of being converted into energy, the food you eat is stored in the body, leading to fat build-up! 

Key Point: The struggle to lose weight increases in difficulty as we age, due to a slowing metabolism. In this article, we explain how and why this slow-down occurs and provide tips to mitigate it.

Why Metabolism Decreases with Age and Tips for Improving It

Table of Contents

What is the Metabolism and Why Is It important?

We all know the basics of nutrition science. Food and beverages provide your body with the sustenance it needs to perform daily functions.

Your body converts food intake into energy. The rate at which the body properly absorbs nutrients is determined by the metabolism.

This chemical process includes breaking down the calories and converting them into energy with the help of hydrogen and oxygen.

In turn, the energy produced helps your body in various processes like cellular repair, hormonal functions, and pumping blood. The energy produced continuously helps in essential functions like breathing and digestion.

It is believed that, aside from genetics, several other factors affect your metabolism:

  • Gender
    • Gender plays a key role in how your body converts calories. Men and women are wired differently. Since men generally have more muscles than women, they burn more of what they eat.
    • But ultimately this difference can be mediated by other factors.
  • Body size
    • Body size also affects the metabolic rate. With a large build or substantial muscle mass, you may need to burn more calories to produce energy.
  • Eating habits
    • Your eating habits also affect your metabolism. A balanced diet helps maintain your muscle mass and, in turn, keeps your metabolism healthy. When you eat is just as important as what you eat in terms of metabolic health.
  • Level of Activity
    • Your activity level impacts your metabolic rate as well. Physical activity increases your metabolism, as your body needs to produce more energy.
  • Aging
    • Metabolism slows down with age. As people become older, they also gain weight and experience reduced muscle mass. When neglected, these can lead to other complex health concerns.

The recommended daily calorie intake is about 2,000 calories. A good metabolism will help your body to breakdown these calories into energy, instead of storing it as fat.

Ever wonder what a 2,000 calorie diet looks like? Here’s a video with some examples:

The Bottom Line: While aging represents a major factor in slowing metabolisms, these other factors play a crucial role as well. Since we can’t control the rate at which we age, we need to look closely at these other factors.

senior woman eating healthy

What are the Signs of a Good Metabolism?

Good metabolism points to your body’s capacity to naturally burn off calories you consume at a fast rate, even while at rest.

A good metabolism is usually evident in:

  • Good muscular build
    • If you look and feel healthy, particularly by maintaining muscle mass with a good body composition, chances are, you’re burning enough calories to maintain. As such, you can maintain your lean physique.
    • On the other hand, if you’re noticing that you build muscle but find it difficult to stay lean, then you might be under the effects of a calorie surplus–where your metabolism is not burning calories fast enough.
  • High energy levels
    • A good metabolism ensures you get enough energy by burning down what you eat fast. Alert and active individuals are “fueled” enough to move around and perform their activities efficiently.
  • Healthy skin
    • With good metabolism, your body obtains enough energy for cell repair. This keeps your skin cells fresh and vibrant, which will be visibly noticeable.
    • This also contributes to things like healing and recovery. If your wounds take too long to heal or you notice you stay sore longer after workouts, then it may be a metabolic issue.

Summary: A healthy metabolism contributes to various components of health and activity. At peak function, your metabolism will provide consistent energy, healthy cellular activity, and efficient muscle building and recovery.

What are the Signs of a Bad Metabolism?

The glaring factors that result in bad metabolism changes are high body fat, low-calorie diets, and aging.

Here are the signs for you to look out for that may signal poor metabolic functioning:

  • Weight gain
    • With bad metabolism, you burn fewer calories, and most food you eat is stored as fat. By burning calories at a slow rate, it becomes difficult to lose excess weight.
    • Because aging affects metabolism, older individuals often find it difficult to overcome an increase in weight or body fat.
  • Feeling of sluggishness
    • A changing metabolism may cause you to feel sluggish and act slow. It is due to the lack of energy and nutrients that aren’t properly absorbed and utilized by the body.
  • A variety of health problems
    • A problematic metabolic function often manifests in numerous health issues, including recurring headaches, hair loss, and dry skin.
    • Aging, for example, slows down metabolism and causes hair loss and wrinkled skin.
    • With weight gain caused by slow metabolism comes blood pressure, blood sugar, and cholesterol issues, increasing the risks of stroke, heart diseases, and diabetes.

The Bottom Line: Because a healthy metabolism works as the foundation for all sorts of bodily functions, an unhealthy metabolism may present in many different forms of dysfunction.

How Metabolism Decreases with Age

metabolism decreases with age
Patient dressed in a terry bathrobe using a segmental body composition analyzer

Data from the Pennington Biomedical Research Center indicates that metabolism gradually slows down at a rate of 0.7% every year. Other estimates suggest the rate of slow sits at about 10% per decade of life after 20 years of age.

This is what that looks like:

AgeMetabolic Rate of Slowing
20 years old0% (Optimal)
30 years old7% to 10%
40 years old14% to 20%
50 years old21% to 30%
60 years old28% to 40%
70 years old35% to 50%
80 years old42% to 60%
90 years old49% to 70%

This research clearly verifies the fact that the older you get, the less efficient your metabolism becomes. But what’s interesting is the potential difference in the rate of slow.

If we interpret the difference between a metabolism that slows by 7% each decade and one that slows by a rate of 10% each decade as a function of health, then someone who actively works on maintaining a healthy metabolism will have a much faster one in old age then someone who didn’t work on this.

As people age, muscle mass decreases, and fat tends to make up more of the body weight, which further affects metabolism. This decline in muscle mass greatly affects the rate at which the body burns a certain amount of calories.

Key Point: Individuals who actively build muscle mass as they age, may be able to curtail the rate at which age slows down their metabolism.

Resting Metabolic Rate

Your resting metabolic rate or RMR, which indicates how many calories you burn when completely at rest, gets impacted by aging as well.

Basal Metabolic Rate

It affects your basal metabolic rate or BMR, the minimum calories that your body requires for basic functions.

Did you know that, by typically settling for a sedentary lifestyle, older people reduce their energy expenditure or the number of calories they burn daily?

In other words, as the elderly become less active, they directly lower their BMR and RMR due to this inactivity. This means their metabolism burns fewer calories daily.

Growing Health Concerns for Aging Populations

New research from Duke University suggests that this health concern must be addressed among older age groups.

Because inactivity is linked to poor metabolic function, aging people often find themselves in a cycle of dysfunction:

  • Inactivity leads to poor metabolic function
  • Poor metabolic function leads to low energy levels, weight gain, and feeling sluggish
  • Low energy levels, weight gain, and feeling sluggish leads to further inactivity

While this article primarily puts the spotlight on aging and metabolism, we emphasize that these factors can deteriorate the body’s ability to burn calories and absorb nutrients.

Specifically, here are some other poignant observations of this research.

  •  Abrupt changes in your diet may also drive your body to store energy instead of processing it.
  • Hormonal problems and thyroid dysfunction slow down your metabolic process. These conditions require immediate medical attention.

Bottom Line: The vicious cycle between slowing metabolisms and decreased activity put aging populations at high-risk for various health issues.

seniors working out

Tips for Mitigating a Slowing Metabolism

Growing old may be inevitable, but a deteriorating metabolic rate doesn’t have to be!

Here are proven tips to maintain a strong metabolism even as you age:

  • Get enough sleep.
    • Sleeping less than the recommended 7 or 8 hours may significantly affect your metabolism.
    • Sleeping too little reduces your energy levels, and can lower your RMR and even your BMR.
    • Some studies link food cravings with a lack of sleep, which results in unwanted binge eating and elevated body fat.
  • Move more often.
    • A sedentary lifestyle leads to more stored energy or accumulated fat, so stay active and build the daily workout habit.
    • The goal is to train your body to burn its calories instead of storing them. Strength training and cardio both work.
    • Gain muscle with physical activities and strength training. Try low-impact activities like brisk walking, aerobics, and yoga, which are generally recommended for older individuals.
  • Watch what you eat. Eat your way to a good metabolism, as they say!
    • Include whole grains, vegetables, and lean proteins in your diet to obtain lean muscle mass.
    • Improve your digestion and metabolism with a high-fiber diet.
    • Avoid any calorie-deficit diets and other diet fads that mess up your metabolism.
    • Never skip meals unless following a well-researched plan for intermittent fasting.
  • Stay hydrated.
    • Getting enough liquid into your system will aid your body’s metabolic function.
    • Drink one glass of water before your meals to maintain proper hydration.
    • Drinking cold water can provide a slight boost to metabolism since your body has to work to warm it up.
    • Drink green tea to help your body become efficient at digesting food.
    • Avoid sugar-laden energy drinks.
  • Keep the temperature in your room or home at the proper levels.
    • While a cool temperature may cause your metabolism to increase, staying in an extremely cold place may also cause you to eat more and affect your metabolism negatively.
    • Make sure you’re sleeping in a cool bedroom at night (65-68), as this may provide a metabolic boost as well.
  • Stock up on Omega-3.
    • Not all fats, like Omega-3, are bad for you.
    • Omega-3 fatty acids commonly found in salmon, tuna and mackerel can boost your metabolism.
    • Omega-3 also helps with your heart health and prevents cardiovascular disease.

We also recommend looking into the best pre workout supplements and thermogenic supplements. These tools can help you push yourself to increase your calorie expenditures.

Bottom Line: Because our metabolisms slow linearly throughout life, you shouldn’t wait to build these good habits. Follow these tips to ensure healthy metabolic function throughout each phase of life.

energy expended versus reduced energy expenditure


Aging causes changes in your body, and slow metabolism is one of them.

Decreased metabolism affects the way your body burns energy. It impacts your weight, energy levels, and body functions—and poor lifestyle choices and practices such as sedentary living and unhealthy eating can exacerbate the situation!

The good news, however, is this: you can do something to fight off the metabolic issues as unwanted effects of aging.

The fundamentals of staying healthy—such as getting enough sleep, maintaining a healthy diet and a healthy weight, and doing proper exercise to keep those energy expenditures high—can all make a difference in your metabolism.

That said, certain age-related metabolic issues may require evaluation and help from the experts. Talk to your doctor to better know your metabolic condition.

Key Takeaway: Aging is an inevitable part of life, however that doesn’t mean you should wait to address metabolism issues until later in life. Start building healthy habits for an optimized metabolism early in life to avoid issues later on.

Jack Kelle

Jack is an entrepreneur, outdoorist, and animal lover with a background in philosophy, psychology, and business. He enjoys music, friends, and family. At RAVE, Jack works as the manager of marketing and content development.