Is Our Metabolism to Blame for the "Middle-Age Spread"?

Do you remember when you were in your teens and early twenties, and it seemed like you could eat anything you wanted without gaining weight? Then, suddenly, that ability vanished as you passed 40. 

You were likely told that this was an inevitable effect of age, as your metabolism had slowed down. It turns out that this idea is a myth. A myth that has just been busted by science.

What Did We Think and Why?

The old belief is that people over 40 experience a drop in metabolism, making it harder to lose or maintain weight. It's even worse for women, who have a naturally lower metabolism, which will slow even further once they reach menopause. This is known as the "middle-age spread". 

It was an understandable belief, as people usually gain weight as they get older, particularly once they enter their 40s. The hormonal changes associated with menopause can cause weight to be distributed differently, and metabolic diseases such as diabetes and cardiovascular disease tend to spike in middle age. 

Also, researching metabolism over lifetimes is a costly and time-consuming process, which means that previous studies have only been small-scale operations. But that has recently changed.  

What Does the New Research Say?

The most recent metabolism research included over 6,600 participants, ranging from one week to 95 years old. These participants included both men and women, and they were spread out over 29 different countries. These broader parameters revealed some fascinating results.

Rather than our metabolism spiking in our teens and plummeting in our 40s, the research established four different periods where our metabolism changes. 
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• During the first 12 months of life, a baby's metabolism will explode. Infants have the highest energy needs of all when measured by weight.
• After this initial boom, the child's metabolism will slow by about 3% per year until their 20s. At this point, it will level off. When the researchers took body size into account, a teenager's growth spurt didn't raise their metabolism, as we previously thought.
• Once in their 20s, an adult's metabolism will then stay stable well into middle age. This is contrary to the popular belief that the metabolic rate falls from the 20s onwards.
• When an adult reaches the age of 60, their metabolism will start to decline again at a rate of 0.7% per year. By the time they reach their 90s, they will need 26 fewer calories per day than when they were in their forties. ​

What Does That Mean For Us?

Sadly, this means that we can't use age as an excuse for gaining weight anymore. But in a way, this is good news. Rather than being held captive by your metabolism, you can do something about it.

If metabolism isn't to blame, then what is? Just because our metabolism doesn't change as we get older, it doesn't mean other aspects of our lives either. 

Sitting Too Much
One of the most common reasons for weight gain is a sedentary lifestyle. Many people have office jobs where they spend most of their day sat at a desk. This means that they experience little NEAT (non-exercise activity thermogenesis). NEAT is the calories burnt for everything that doesn't include sleeping, eating, or exercise. As we get older, we spend more time sitting down and being more still, which burns fewer calories than standing, walking, or even fidgeting. Thankfully, this is an easy fix. You can invest in a standing desk or even get up and walk around now and then. 

Workout Schedule Falls Apart
Middle-aged adults also find it more challenging to maintain a structured training routine. They get ill more and pick up injuries more often. They might have children, which take up a lot of formerly free time. However, there are still ways that you can keep active. Light exercise, such as hiking, can reduce the risk of injury. If you have children, then spend time doing something active with them. You'll not only keep yourself moving, but you can also teach good habits.
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Too Much Food
We can also be guilty of eating more than we think. Your children might leave leftovers, and it's a shame to let them go to waste. Those sweet, milky drinks that are full of calories are so comforting. Also, who keeps track of those nibbles we work our way through as the day goes on? Try keeping a diary for a week or so of what you eat, and you should spot those hidden calories. ​

​Conclusion

By blaming the middle-age spread on a naturally falling metabolism, many people gain weight when they don't have to. However, once you know what's causing the problem and what's not, you can do something about it.