Metabolism slower with age? These are the reasons why!

You've probably already been told that as you get older you won't be able to eat the way you did when you were younger. This is because theMetabolism with increasing ageslows down, making it easier to gain a few extra pounds and harder to lose them. Some reasons for this are muscle loss, lack of exercise and the natural aging of the metabolism. Fortunately, there are many things you can do to counteract these age-related metabolic changes.In this article, you'll learn why your metabolism slows as you age and what you can do about it.

What exactly is metabolism?

Simply explained, your metabolism is the set of chemical reactions that keep your body alive. He also determines how manycalories per dayburn. The faster your metabolism, the more calories you burn.

The speed of your metabolism is influenced by four key factors:

  • Ruheumsatz (Resting metabolic rate, RMR):How many calories you burn while resting or sleeping. This is the least amount you need to stay alive and functioning.
  • Thermal Effect of Food (TEF):How many calories you burn by digesting and absorbing food. TEF is typically 10% of calories burned daily.
  • Movement: How many calories you burn through exercise.
  • Non-exercise-induced thermogenesis (NEAT):How many calories you burn through non-exercise activities, such as: B. by standing, fidgeting, washing dishes and other household tasks.

Other factors that can influence your metabolism include age, size, muscle mass and hormonal and genetic predispositions. Unfortunately, research shows that metabolism slows as we age. Some reasons for this are lack of exercise, muscle loss and aging of the internal organs.

Metabolism slows down as you get older because you move less

Research shows thatthe physical activitydecreases with increasing age. Less exercise can significantly slow your metabolism, accounting for 10-30% of your daily calorie burn. For very active people, this proportion can even be up to 50%.

At theThermogenesis without physical activity (NEAT)These are the calories burned by activities other than exercise. This includes activities such as standing, washing dishes and other household chores. Unfortunately, seniors tend to be less physically active and burn fewer calories through exercise. An active lifestyle can prevent these metabolic changes.

A study (1) with 65 healthy young people (21-35 years) and older people (50-72 years) showed that regular endurance training prevents metabolism from slowing down in old age.

Not only metabolism, but also muscle mass decreases with age

The average adult loses 3-8% of their muscle every decade after age 30. Research even shows that...At the age of 80, you have around 30% less musclethan at 20. This age-related muscle loss is calledSarcopeniaand can lead to broken bones, weakness and early death. Sarcopenia also slows metabolism because more muscle increases resting metabolism.

A study (2) of 959 people found that people aged 70 had 9 kg less muscle mass and an 11% slower resting metabolic rate (RMR) than people aged 40.

Since theMuscle mass depends on activity level, lack of exercise is one reason why you lose more muscle as you get older. Other reasons include lower calorie and protein consumption and reduced production of hormones such as estrogen, testosterone and growth hormone.

Metabolic processes slow down with age

How manyCalories you burn at rest (RMR), is determined by chemical reactions in your body. Two cellular components that control these reactions are theSodium-potassium pumps and the mitochondria.

The sodium-potassium pumps help generate nerve impulses and muscle and heart contractions, while the mitochondria generate energy for your cells. Research shows that both components become less efficient with age, thus slowing down metabolism.

In one study (3), for example, the speed of theSodium-potassium pumpsof 27 younger men and 25 older men. Pumps were 18% slower in older adults, causing them to burn 101 fewer calories per day.

In another study (4) changes in theMitochondriacompared between 9 younger adults (average age 39 years) and 40 older adults (average age 69 years). The scientists found that older adults had 20% fewer mitochondria. Additionally, their mitochondria were almost 50% less efficient at using oxygen for energy - a process that fuels metabolism.

However, compared to physical activity and muscle mass, these internal components havea smaller influenceon the metabolic rate.

How much does metabolism slow down as we age?

How fast your metabolism works depends on your physical activity level, muscle mass, and various other factors. Thereforethe metabolic rate variesfrom person to person.

For example, in one study (5), the basal metabolic rate of three groups was compared: 20 to 34 year olds, 60 to 74 year olds and those over 90 years old. Compared to the youngest group, those aged 60 to 74 burned about 122 fewer calories, while those over 90 burned about 422 fewer calories. However, after accounting for differences in gender, muscle and fat, the scientists found that those aged 60 to 74 burned just 24 fewer calories, while those over 90 burned an average of 53 fewer calories each day. This shows that theBuilding and maintaining musclesis incredibly important in old age.

In another study (6), 516 older adults (over 60 years of age) were followed for 12 years to see how much their metabolism decreased per decade. Taking differences between muscle and fat into account, women burned 20 fewer calories per decade at rest, while men's calorie expenditure decreased by 70 calories. Interestingly, both men and women were also less active, burning 115 fewer calories per decade from activity. This shows that staying physically active as you age is crucial to maintaining your metabolism.

In short, research seems to show thatthe low physical activityandthe muscle breakdownhave the greatest negative impact on metabolism.

How can you prevent your metabolism from slowing as you age?

Although metabolism slows as we age, there are many ways to combat it. Here are 6 of them:

1. Try strength training
This form of training improves muscle strength and endurance and can help prevent metabolism slowing.

2. Or with high-intensity interval training
High-intensity interval training (HIIT)is a training technique in which intensive anaerobic exercises alternate with short periods of rest.

3. Get enough sleep
Research shows that lack of sleep can slow down your metabolism. Fortunately, a good night's sleep can reverse this effect.

4. Eat more protein foods
Eating protein-rich foods can boost your metabolism as you age because your body burns more calories as you digest and absorb them. This is known as the Thermal Effect of Food (TEF). Foods rich in protein have a higher TEF than foods rich in carbohydrates and fat.

5. Make sure you eat enough
A low-calorie diet can slow metabolism by putting the body into “starvation mode.” Older people also have less appetite, which can reduce calorie intake and slow metabolism. If you're having trouble getting enough calories, try eating smaller portions more often. It's also good to have high-calorie snacks like cheese and nuts on hand.

6. Drink green tea
Green teacan increase your metabolism by 4-5%. That's because green tea contains caffeine and botanicals that have been shown to increase resting metabolism.

References:
1)Studyin The Journal of Clinical Endocrinology & Metabolism / (1997)

2)Study:Effect of muscle mass decrease on age-related BMR changes (1977)
3)Study: Sodium-potassium pump activity contributes to the age-related decline in resting metabolic rate (1993)
4)Study: Oxidative capacity and ageing in human muscle (2000)
5)Study: Aging, Resting Metabolic Rate, and Oxidative Damage: Results From the Louisiana Healthy Aging Study (2009)
6)Study: Longitudinal changes in energy expenditure in an elderly German population: a 12-year follow-up (2009)