Metabolic age test: What it is and how it impacts your health

In our journey to optimal health, numbers often play a pivotal role. We count calories, measure weight, and track steps. However, a number is gradually gaining prominence in health circles, and it might reshape how we understand our body’s well-being: metabolic age. 

Unlike our chronological age, which counts the years we’ve been alive, our metabolic age provides deeper insights into our body’s internal health and vitality.

It shows how efficiently our body converts food into energy and indicates whether our physiological health aligns with our age. 

A discrepancy between these two ages can be an eye-opener, prompting us to re-evaluate our lifestyle choices.

This article dives into the intricacies of metabolic age, explaining its significance, how it’s determined, and what it reveals about our overall health.

What is metabolic age?

At its simplest, metabolic age compares an individual’s Basal Metabolic Rate (BMR) – the rate at which the body expends energy or burns calories while at rest – to the average BMR for people of the same chronological age [1]. 

If your metabolic age is lower than your actual age, it suggests that your body is functioning more efficiently than the average for your age group. Conversely, a higher metabolic age indicates the opposite, implying potential health concerns.

Factors influencing metabolic age

A range of factors can play into one’s metabolic age. 

1. Genetics

Some individuals naturally possess a faster metabolism due to their genetic composition. This foundational aspect can set the baseline for one’s metabolic age.

2. Muscle mass

Muscle tissue is more metabolically active than fat, burning more calories at rest. Hence, those with greater muscle mass typically have a lower metabolic age.

3. Diet and nutrition

The quality of one’s diet plays a significant role. Nutrient-rich foods support metabolic processes, while excessive consumption of processed foods can hinder metabolic efficiency.

diet and nutrition
Photograph: KaikaTaaK/Envato

4. Physical activity

Regular exercise, especially strength training, can elevate the metabolism by increasing muscle mass. Conversely, a sedentary lifestyle can contribute to a slower metabolism and potentially a higher metabolic age.

5. Hormonal balance

Hormones, particularly thyroid and insulin, directly impact metabolic rates. Any disruption or imbalance in these can lead to changes in metabolic function and subsequently influence metabolic age.

6. External factors

Elements like stress and sleep patterns can affect metabolic function. Chronic stress and lack of restorative sleep can slow down metabolic processes, potentially leading to an increased metabolic age.

Why metabolic age matters

The intrigue around metabolic age arises from its potential as a holistic health indicator. Rather than just providing a number, it offers context. For instance, two individuals might both be 30 years old chronologically. 

Still, if one has a metabolic age of 25 and the other 40, their bodies are functioning, metabolically speaking, as if they were those respective ages.

This discrepancy can provide critical insights into their internal health and vitality, guiding lifestyle decisions, dietary choices, and fitness routines.

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What does your metabolic age tell you about your health?

Your metabolic age is a barometer for your body’s internal efficiency, revealing how effectively it converts food into energy compared to the average for your chronological age [2]. But its implications run deeper, painting a broader picture of your health.

Efficiency of metabolic processes

A younger metabolic age indicates that your body’s metabolic processes function optimally. In contrast, an older metabolic age might suggest inefficiencies, possibly pointing to issues in nutrient absorption, energy conversion, or hormone regulation.

Risk of chronic diseases

An older metabolic age could highlight an increased risk for certain chronic conditions, such as obesity, diabetes, or cardiovascular diseases. It suggests the body may be under stress or not functioning at its peak.

Physical fitness levels

A more youthful metabolic age often aligns with higher muscle mass and better cardiovascular health. It’s an indirect nod to one’s fitness level, suggesting regular exercise and strength training pay off.

Lifestyle and dietary habits

Metabolic age can reflect lifestyle choices. A diet rich in processed foods, coupled with a sedentary routine, might lead to a higher metabolic age, emphasizing the need for healthier habits.

What is a metabolic age test? 

The metabolic age test is a specialized assessment designed to determine how efficiently your body operates compared to the average efficiency of individuals in various age groups. 

The test employs a method known as indirect calorimetry, where participants breathe into a mouthpiece or mask [3].

This process measures oxygen consumption and carbon dioxide production, providing insights into the body’s basal metabolic rate (BMR) – the rate at which one burns calories while at rest.

The resulting data is then compared against standards set for different age groups. For instance, if a 40-year-old person’s BMR aligns more with the average BMR of a 30-year-old, their metabolic age is deemed to be 30.

Conversely, if their BMR matches that of a 50-year-old, their metabolic age would be considered 50.

How is metabolic age calculated?

Determining your metabolic age involves understanding how efficiently your body produces energy. The concept revolves around the Basal Metabolic Rate (BMR) — the energy or calories your body expends while at rest. 

Metabolic age essentially compares your BMR to the standard BMR of your chronological age peers. But how is this crucial number calculated?

Basal Metabolic Rate (BMR)

BMR is the starting point. It accounts for the calories the body burns at complete rest, supporting essential functions like breathing, blood circulation, and cellular processes. 

To determine BMR, several formulas exist, with the Harris-Benedict [4] and Mifflin-St Jeor [5] equations being among the most popular. These calculations factor in gender, age, weight, and height.

Harris-Benedict equation

  • For Men:
    • BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) – (5.677 x age in years)
  • For Women:
    • BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) – (4.330 x age in years)

Mifflin-St Jeor equation

  • For Men:
    • BMR = (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) + 5
  • For Women:
    • BMR = (10 x weight in kg) + (6.25 x height in cm) – (5 x age in years) – 161

Comparison with age groups

Once the BMR is established, it is compared with average BMR values across different age groups. If your BMR is higher than the average for your age, your metabolic age will be younger, and vice versa.

Advanced metabolic testing equipment

Beyond traditional calculations, specialized devices and equipment provide more accurate BMR measurements. Indirect calorimetry measures an individual’s metabolic rate by measuring carbon dioxide produced and oxygen consumed.

Online calculators

Numerous online platforms and apps offer metabolic age estimations. While convenient, it’s crucial to approach these cautiously, as their accuracy might vary. They often employ generalized formulas and may not consider all individual factors.

Consideration of other factors

While BMR is the foundation, determining metabolic age holistically might also involve evaluating muscle mass, fat percentage, and even specific metabolic blood markers to paint a clearer picture.

Metabolic age vs. chronological age

When navigating health and wellness metrics, two distinct age types often come into discussion: chronological age and metabolic age. Both carry significance, but they illuminate different aspects of an individual’s health and well-being. 

Let’s examine these two concepts’ differences and understand why each is vital.

Chronological age

This is the most straightforward concept of age and one we are all familiar with. It simply denotes the number of years an individual has lived since birth. It’s an objective measure, rooted in the passage of time, and it’s inescapable. 

Every year, our chronological age ticks up by one on our birthday. While it provides insights into life stages and milestones, it doesn’t necessarily give a comprehensive view of an individual’s health.

Metabolic age

Unlike chronological age, metabolic age provides a subjective measure that can vary from person to person, even if they share the same birth year. It represents how your body’s metabolism functions relative to a standard set for different age groups. 

In essence, it gauges the efficiency of your body’s metabolic processes. If your metabolic age is younger than your chronological age, it suggests your body is functioning at an optimal or even better rate than the average for your age. 

Conversely, a higher metabolic age could be a sign that there are areas of your health that might need attention.

Why the distinction matters

Understanding the difference between metabolic and chronological age is essential for several reasons:

Holistic health insight

While chronological age is fixed, metabolic age offers a dynamic perspective on health, revealing how lifestyle, diet, exercise, and other factors influence bodily functions.

Guiding lifestyle choices

Recognizing a disparity between one’s metabolic and chronological age can be a wake-up call. For instance, a 30-year-old with a metabolic age of 40 might be spurred to reevaluate dietary habits, incorporate more exercise, or seek medical advice.

Predictive value

A significantly higher metabolic age might indicate a predisposition to specific health challenges, even if they haven’t manifested yet. This can provide a proactive approach to health management.

Beyond numbers

While chronological age provides a concrete timeline of life, metabolic age delves deeper, painting a picture of one’s internal systems functioning. It tells a story beyond just numbers.

While chronological age marks life’s journey in years, metabolic age offers insights into the journey of health and vitality.

Together, they provide a comprehensive view, allowing individuals to celebrate milestones while ensuring the journey is as healthy and vibrant as possible.

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Why it’s important to know your metabolic age?

Understanding your metabolic age offers more than just a number; it provides a window into the state of your health. Here are some notable benefits of being aware of this metric:

1. Tailored health goals

Knowing whether your metabolic age is younger or older than your chronological age can help set specific and realistic health objectives. For instance, someone aiming to decrease their metabolic age might focus on muscle-building exercises or dietary changes.

2. Lifestyle accountability

Recognizing a higher metabolic age can motivate reassess and adjust lifestyle choices, including diet, physical activity, and stress management.

3. Predictive health insights

A metabolic age that’s significantly older can signal potential health risks. It allows individuals to take proactive measures, such as regular health screenings, even before symptoms manifest.

4. Enhanced motivation

Witnessing a reduction in metabolic age over time can serve as a testament to the positive effects of health interventions, boosting motivation to maintain or even intensify healthy practices.

5. Personalized interventions

Metabolic age can guide healthcare professionals in providing personalized advice and treatments, ensuring that interventions are tailored to individual needs.

How to improve your metabolic age

Metabolic age, as an indicator of internal health and metabolic efficiency, can be influenced by various factors. The good news is that it’s not set in stone. It is possible to lower your metabolic age by adopting certain lifestyle habits and making informed choices. Here’s a comprehensive guide on how to do just that:

1. Make dietary changes

  • Balanced nutrition: Ensure your diet includes a mix of proteins, healthy fats, and complex carbohydrates. Include plenty of fresh fruits and vegetables rich in antioxidants, which can help combat free radicals and support metabolic functions.
  • Stay hydrated: Drinking sufficient water aids metabolic processes. Water is crucial for cellular functions and helps in the efficient elimination of waste products.
  • Limit processed foods: Reducing the intake of high sugar, salt, and processed foods can positively impact metabolism. These foods can lead to weight gain and reduce metabolic efficiency.
stay hydrated
Photograph: khwanchai14/Envato

2. Maintain physical activity

  • Strength training: Muscle is metabolically active. Strength training exercises can increase muscle mass, boosting your BMR (Basal Metabolic Rate).
  • Aerobic exercises: Cardiovascular activities like running, cycling, or swimming increase heart rate and improve metabolic function.
  • Consistency: Instead of intense, sporadic workouts, aim for consistent, daily physical activity. Even walking 30 minutes daily can make a significant difference.

3. Manage stress 

  • Mindfulness practices: Activities like meditation, deep breathing exercises, and yoga can reduce stress, which is beneficial for metabolic health.
  • Adequate sleep: Sleep is rejuvenating. Ensure you get 7-9 hours of quality sleep, as chronic sleep deprivation can adversely affect metabolism.
  • Disconnect: In our always-connected world, taking time off screens and indulging in hobbies or spending time with loved ones can significantly reduce stress levels.

4. Limit harmful habits

  • Reduce alcohol: Excessive alcohol consumption can reduce the body’s metabolic efficiency. It’s recommended to limit intake and consume in moderation.
  • Quit smoking: Smoking affects lung function and can decrease metabolic efficiency. Quitting smoking has myriad health benefits, including a potential improvement in metabolic age.

5. Get regular health check-ups

  • Hormonal balance: The thyroid gland, in particular, plays a significant role in metabolism. Regular check-ups can ensure that your hormones are balanced and not affecting your metabolic age.
  • Stay informed: Keeping tabs on other health markers such as blood sugar, cholesterol, and blood pressure can provide insights into your overall health, which can influence your metabolic age.

6. Stay socially active

  • Community engagement: Being part of community activities or groups can reduce feelings of isolation or loneliness. A positive social environment can indirectly benefit metabolic health.
  • Learning and mental stimulation: Engaging in activities that stimulate the mind, such as reading, puzzles, or learning new skills, can keep the brain active and have holistic health benefits.

7. Take supplements 

  • Vitamins and minerals: While it’s best to get nutrients from whole foods, supplements like vitamin D, magnesium, or omega-3 fatty acids can support metabolic functions, especially if there’s a deficiency.
  • Consult a professional: Before starting any supplements, it’s essential to consult with a healthcare provider to ensure they’re right for you.

Closing thoughts

Your metabolic age offers a unique lens into your health, reflecting the harmony between lifestyle choices and bodily functions. While it’s a dynamic measure, it’s malleable, allowing for improvement and optimization. 

By embracing balanced dietary habits, consistent physical activity, stress management, and regular health check-ups, one can steer their metabolic age toward a more favorable number. 

Ultimately, the journey towards improving metabolic age is an invitation to a healthier, more vibrant life, urging us to be proactive participants in our well-being and to cherish the intricate dance between time and health.


What is a good metabolic rate age?

A good metabolic age is at or below your chronological age, indicating that your body’s metabolic functions are operating efficiently for your age group. If your metabolic age is younger than your actual age, it suggests that your lifestyle and health habits are positively impacting your metabolism.

What is metabolic testing and why is it used?

Metabolic testing measures the rate at which your body burns calories and uses oxygen during rest or during different activities. It is used to determine individual caloric needs, optimize workout routines, and assess metabolic health.

What is the difference between metabolic rate and age?

Metabolic rate refers to the speed at which one’s body expends energy or burns calories, while metabolic age represents how one’s metabolic rate compares to the average rate for different age groups. In essence, while metabolic rate quantifies energy expenditure, metabolic age offers a comparative insight into metabolic efficiency relative to one’s chronological age.

How is metabolic testing done?

Metabolic testing is typically conducted using indirect calorimetry, where a person breathes into a mouthpiece or mask to measure oxygen consumption and carbon dioxide production. This data provides insights into how efficiently the body is converting food into energy, revealing one’s resting metabolic rate (RMR) and caloric needs.

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