The Real Reason Why You Gain Weight as You Age (Hint: It’s Not Your Diet)

The secret behind your weight gain, revealed—plus, what you can do to prevent it.


Wishing you could get your 25-year-old metabolism back? You’re in good company. But don’t blame your eating habits, or even longer hours at the office. Among the many reasons why the pounds accumulate as your years do—including hormones, lack of sleep, and a more sedentary lifestyle—one major explanation is a bit more surprising: muscle loss.

Your muscle mass takes a dive around age 30, and that decline (called sarcopenia) speeds up around age 40, according to Dr. Caroline Apovian, the Director of the Nutrition and Weight Management Center at the Boston Medical Center, professor at the Boston University School of Medicine, and the vice-president of The Obesity Society. Thankfully, sarcopenia is nothing to be too worried about; it happens to everyone as they age.

However, “unless something is done to actively protect and build up that lean muscle mass, our bodies will require fewer calories, our metabolisms will slow, and the lost muscle will be replaced by fat,” Dr. Apovian told Woman’s Day. Hence that bothersome weight gain.

Again, adding a few pounds as you age is completely natural. But if you want to keep the weight off, experts have a few suggestions. Weight-lifting at least twice per week, getting plenty of sleep (the National Sleep Foundation recommends between seven to nine hours for adults), and eating a diet rich in lean protein can prevent sarcopenia, Dr. Apovian says. Tired of the same old turkey sandwich for lunch? Try these 11 healthy ways to load up on lean protein.

And try not to skip meals! “Eating regularly will help you stay energized for strength training, keep your metabolism stoked, and keep the urge to overdo it at any given meal at bay,” Jaclyn London, MS, RD, CDN, Nutrition Director at the Good Housekeeping Institute, told Good Housekeeping.

You can finally say goodbye to that pesky pooch problem. Learn even more things experts won’t tell you about weight loss.

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Brooke Nelson
Brooke is a tech and consumer products writer covering the latest in digital trends, product reviews, security and privacy, and other news and features for