Why Losing Weight Gets Harder After 40

It’s a fact of life: as you get older losing weight becomes more and more difficult. 

This can happen for a variety of reasons like: increased stress levels, a slowing metabolism, or from loss of muscle. 

All we know is that shedding that excess weight takes more effort and intention than it did when we were in our 20’s and 30’s; and that can be frustrating if you don’t understand why.

So, Why Is That?

Here’s a closer look at why losing weight can be so challenging after 40.



It can be so frustrating to older women that continue to gain weight while the men over 40 in their lives just seem to lose the weight easily. This is due to the Testosterone in their bodies. 

Men as they age tend to have a more slender physique than women of the equal age. We know, we know, that hardly seems fair. Testosterone sticks to fat, meaning that less fat lingers around the middle which is why some Men stay skinny as they age while the rest of us don’t.

  • Testosterone also helps to build muscle, fuels metabolism, and maintains insulin sensitivity (which prevents diabetes). 

But, don’t think Men have it so easy yet! 

For men over the age of 40, having Lower testosterone levels is very common, and this makes it easier for the body to store fat.

As men age, testosterone levels naturally decrease at a rate of about 1% a year after the age of 30. This is when that extra weight gain for some men start to creep in and they develop what we call the “dad bod” or the “spare tire”.  

  • Obesity in men also impairs the production of testosterone, so for a good portion of men over 40 it becomes a vicious cycle.


The female body has a delicate balance of progesterone and estrogen; and having higher levels of estrogen are what contribute to fat tissue formation. 

In younger women, estrogen is offset by strong levels of progesterone but, from the age of 35 and onwards the levels of both these hormones decrease leading up to menopause

  • These hormonal changes that come with menopause might make women more likely to gain weight. 
  • Weight gain is also naturally related to aging, as well as lifestyle and genetic factors.

Loss of Muscle

One of the primary reasons losing weight is harder to do as you grow older is due to a slowing metabolism.

It is estimated that your metabolism slows down 5% every decade after you turn 40. This can occur because of the loss of muscle (or sarcopenia) which plays a crucial part in maintaining your metabolism.

  • A decrease in muscle mass is also accompanied by an increase in fat mass which consequently changes your body composition.

..which leads us into this next part..

Fat Increase

There are a number of reasons why we put on the pounds as years go by. 

As you age you may not be able to maintain the same dietary behaviors without gaining the extra weight. Keeping your caloric intake exactly the same as when you were younger can result in unburned calories ending up as fat quickly. 

If you’re not as active as you were 20 years ago (which majority of us aren’t) you definitely can’t eat your favorite pint of ice cream at 10pm at night anymore and expect to burn it off as fast as you did in your younger years. 

When you don’t change your eating habits as you age not only do you lose muscle more rapidly, but your body retains the fat more easily. That fat increases more and more as you age because you have less energy throughout the day, which also means your metabolism slows.

The energy you have (or don’t have) during the day is delivered to your body in the form of calories which is why the weight goes on easier than it did when you were younger. 

We all have made the comment, “If I was that young again I could do….” 

In a nutshell- When you were younger you had more energy, you could eat junk food without worrying and you could burn calories twice as fast because of younger muscle mass and a faster metabolism.

High Stress Levels

Stress can play a significant role in weight gain as we age. It could be contributed to our demanding jobs or even the stress that comes with raising our children. 

People also tend to eat as a way to cope with stress to make themselves feel better. 

Prolonged chronic stress can also lead to hormonal changes that may increase your appetite and cause cravings for higher-calorie comfort foods, such as ice cream, chips, and pizza. 

We already know why eating higher-calorie comfort foods is not good for you, and how it makes you gain weight with age.

What can you do to stop or control the weight gain?

Many things change as we age, especially our bodies. By being cautious about the foods you are consuming, maintaining a regular exercise routine and getting an adequate amount of sleep, you can help maintain a slimmer physique longer.

Age is just a number. Don’t let it define you.

If weight gain is still a big concern for you, you can start on a custom weight loss program.

If you’re located in or near Atlanta, GA., the Atlanta Medical Institute, can help you adopt healthy habits and start on a customized weight loss program that will help lose that weight and keep it off. 

Just set up an assessment with us to go over options with one of our weight loss physicians. Or call us directly at (404) 800-0812.
Don’t let your age define what you can still control. Get started today and get back to looking and feeling like you did 10 years ago.

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Atlanta, GA 30342

Phone: (404) 800-0812
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