What your metabolic age really says about your health (and how to calculate it)

How old do you feel today? 25, or a very weary 100? As the saying goes, ‘age is just a number', and there’s plenty of truth in this when it comes to your health – the amount of years that you’ve been alive isn't always an indicator of your fitness.

If you’re yet to discover your metabolic age, discover why this digit matters, along with the steps you can take to make yourself ‘metabolically’ younger. Who's ready to turn back the clock?

What is your metabolic age?

In a nutshell, your metabolic age is based on what’s called your Basal Metabolic Rate – often known as just BMR, compared to the average BMR of someone of the same age. "Your BMR tells you how many calories your body burns while resting, and it’s a good gauge of your efficiency in burning the calories you consume," explains Simon Bradeley, a health coach at Tanita, the leaders in body composition monitors.

Why does your metabolic age matter?

It’s an important indicator of how hardworking your metabolism is. It also steps away from using your ‘real age’, or the number on traditional weighing scales, to define your fitness. "Your metabolic age shifts the focus away from weight and focuses more on your body’s structure, or composition, of muscle and fat," says Simon.

“BMR reduces as we get older and often contributes to the fact that we may gain weight as we age - despite the fact we may be following the same diet we've always done," says Dr Rekha Tailor, cosmetic doctor at Health and Aesthetics. "Knowing your BMR can help you feel less frustrated, especially if you're on a weight loss journey or want to give your general health an overhaul, and feel like you're not making progress." 

Continuing she adds, "Whatever your BMR measurement there's always room for improvement, and there are a number of concrete steps you can take to put it on a downward curve."

How do you calculate metabolic age?

It’s possible to use a person’s height, weight and age to estimate BMR, but using body composition technology is much more reliable, says Simon. "A body composition analyser will also give accurate readings on everything from your muscle mass to how much visceral fat you have."

At home, try the Tanita BC-401 monitor (£78, johnlewis.com). Or, many private health screening packages – such as the Bluecrest Health Active Check ( £129, bluecrestscreening.com), will also include a body composition scan as standard.

What does your metabolic age mean for your health?

The fitter, healthier, and stronger you are, the lower your metabolic age will be. "Muscle burns more than fat, which means someone who has a high level of muscle mass will burn more calories sat down, then someone with a lower muscle mass," says Simon.

If your metabolic age is younger than your actual age, this is great news and shows you’re in good shape – some adults manage to knock 20 years off their real age. If your metabolic age is higher, this is a sign that you need to improve your metabolic rate by changing your diet and fitness habits, and get any possible health problems checked out by your GP.

How to lower your metabolic age

Simple lifestyle tweaks can improve your metabolic age – use these tips to bring that number down.

1. Add more protein to your diet

"Your body burns more calories digesting protein-rich foods than fat-rich foods, which means eating more protein can help fight an ageing metabolism," says Simon. Look to have a source of protein in every meal.

2. Build fat-free mass (FFM)

"BMR is strongly correlated with fat-free mass (FFM). While fat burns very little energy, muscle is an active tissue that uses up energy even whilst at rest," reveals Hannah Braye, Nutritional Therapist at Bio-Kult.

"In light of this, one of the most effective ways to increase your BMR is by engaging in exercise that increases your FFM. Resistance, strength and weight training is the most effective at building muscle and increasing BMR."

3. Get enough sleep

Research shows a link between a lack of sleep and a slowing metabolism. "Poor sleep may actually increase muscle loss, so make it a priority," says Simon.

4. Say yes to complex carbs

"The best way to improve your metabolic age is by leading a healthy lifestyle, and diet forms a key part of this," says May Simpkin, Leading Nutritionist and Consultant to Enzymedica UK.

"Eating complex, whole foods that require more energy to break down will help avoid metabolic slowdown. Opt for complex fibre-rich carbohydrates like wholewheat pasta, brown rice and starchy vegetables such as butternut squash and sweet potato."