It’s common knowledge that your metabolic rate slows down as you age. But what if you could reverse that process and rejuvenate your metabolism?
I’m going to show you two simple ways to turn back the clock on metabolic age, so you can look and feel better than you did ten years ago.
Your metabolism is a key factor in determining your energy levels, weight management, and overall health. As we age, it’s natural for our metabolism to slow down, leading to weight gain, fatigue, and other health issues. But with the right strategies, you can reverse this process and boost your metabolism to a younger, healthier state. In this article, you’ll learn how metabolic age is defined, how it changes with age, and the two most effective ways to lower it. You’ll discover how body composition plays a critical role in metabolic age and how to adjust your lifestyle to achieve a younger metabolic profile.
What Is Metabolic Age?
Metabolic age is how your metabolism compares to other people in your biological age group. The comparison is based on your basal metabolic rate (BMR), which is how many calories your body burns at rest.
Your metabolic age is inversely related to metabolic rate.
Specifically, a lower BMR means you have a higher metabolic age, while a higher BMR means you have a lower metabolic age.
How Metabolism Changes With Age
One of the most common ways to calculate BMR is a formula that uses your height, weight, and age. This is called the Harris-Benedict equation.
It’s based on the fact that, in general, your metabolism slows down as you get older. In the chart below, you can see how metabolism gradually declines at a steady rate once you pass the age of 20.
Using this trend, the equation can estimate your BMR according to your age and general body size. However, since it assumes everyone has a similar amount of muscle and fat, it’s not always accurate.
In reality, body composition varies greatly even among people of the same height, weight, and age.
That’s why there’s a second formula for calculating BMR using lean body mass. The Katch-Mcardle equation is based on the fact that the more muscle (lean mass) you have, the higher your metabolic rate.
In fact, for every 10 lbs of muscle, your body burns about 100 more calories daily.
Body Composition and Metabolic Age
To illustrate the effect of body composition on metabolic age, let’s say two ladies are both 5’4″, 150 lbs, and 40 years old. The Harris-Benedict equation says the average BMR for these women is 1,416 calories.
However, one of them has 40% body fat, and the other has 20% body fat.
Using the Katch-Mcardle formula, the woman with 40% body fat has a BMR of about 1,254 calories. Meanwhile, the woman with 20% body fat has a BMR of 1,548.
That makes their metabolic ages 78 and 18, respectively!
Since the first woman has more body fat and less lean mass, her metabolic age is older than her actual age. While the second woman has less body fat and more lean mass, so her metabolic age is younger than her actual age.
The image below makes it easy to see how metabolic age changes with weight and body composition.
Another way to picture the effect of body composition on metabolism is by plotting body weight and body fat percentage. At the intersection of these two numbers is the resulting metabolic age.
With this visual data, you can see how metabolic age changes with body composition for a person of a given height.
Again, more muscle and less fat give you a healthy metabolic age.
These charts show that your metabolic age isn’t fixed like your chronological age.
By changing your body composition, you can actually lower your metabolic age!
2 Ways to Lower Metabolic Age
To reduce your metabolic age, you need to decrease body fat, increase lean mass, or both.
1. Decrease Body Fat
If you’re over 24% body fat for women or 18% body fat for men, you should usually start with fat loss.
The only way to burn body fat is by increasing the number of calories you burn or decreasing the amount you consume.
- Cardiovascular Exercise: Cardio burns a high percentage of calories from stored body fat. High-intensity interval training (HIIT) is popular because it burns more calories in less time. But low-intensity steady-state (LISS) actually burns more calories from fat per minute. Cardio is a good way to burn more calories, but you still have to ensure you eat fewer calories than you burn.
- Create A Calorie Deficit: To create an appropriate calorie deficit, you need to know how many calories you burn daily, also called your total daily energy expenditure (TDEE). It’s best to target a calorie intake that is less than your TDEE but more than your BMR to lose fat sustainably. This moderate approach decreases the likelihood of your metabolism slowing down in response to calorie restriction.
2. Increase Lean Mass
In addition to decreasing body fat, you can lower your metabolic age by increasing lean mass. Remember, the more muscle you have, the higher your metabolism and the lower your metabolic age.
- Lift Weights: The best way to add lean muscle is by incorporating resistance training workouts into your exercise plan. Lifting weights gives your body a reason to build muscles bigger and stronger.
- Eat Enough Calories: To build muscle after your workouts, you must eat at least as many calories as you burn. Or even have a slight calorie surplus. That extra energy is what your body uses to create new muscle. Of course, you can’t simultaneously be in a deficit and a surplus. So it’s generally best to lose excess fat first, then gradually increase your calories to gain muscle while maintaining lower body fat. This is called a lean bulk.
- Increase Protein Intake: Many studies have shown that a higher protein intake results in greater lean muscle gains because protein provides the building blocks your body needs to build new muscle. I’ve found that the best way to calculate your protein intake is to target about 30% of your calories from protein.
Find Your Metabolic Age
When all is said and done, a high or low metabolic age doesn’t have much to do with your overall health or life expectancy. It’s more like a tool to visualize the effect of body composition on your metabolism.
One key takeaway is that you should always consider body composition when calculating your daily caloric needs, especially when your lean mass or body fat is higher or lower than average.
In conclusion, understanding and managing your metabolic age can be a powerful tool for optimizing your health and fitness. By focusing on improving your body composition through fat loss and muscle gain, you can effectively turn back the clock on your metabolism. Remember that consistency is key, and small changes in your diet and exercise routine can lead to significant improvements over time. Whether you’re aiming to lose weight, gain muscle, or simply improve your overall well-being, these strategies can help you achieve a younger, healthier metabolic profile. Ultimately, your metabolic age is not a fixed number but a dynamic indicator of your lifestyle choices.
Ready to take control of your metabolic age? Visit HealthTalk’s metabolic age calculator for a personalized assessment.