How to increase muscle mass for over 40s

Your body will thank you for building and maintaining muscle as you grow older and this dietary tip is essential for over 40s

Man performing a push up outdoors wearing workout gear
(Image credit: Getty)

Muscle mass begins to decline after the age of 40 for many and is harder to maintain as you grow older. But this doesn't mean that building muscle is impossible later in life. In fact, there are small things you can do to increase mass and strength in your muscles, such as adding more fiber to your diet.

While you might think that shifting serious weight is the only way to gain muscle, your diet has a very large role to play in helping your body to increase strength and muscle. Protein is the go-to thing that most people increase when they want to grow muscle and repair muscle, this is why we help people find the best protein powder in  our guides. 

However, recent research looked into the relationship between eating fiber, body mass and muscle mass in adults aged over 40. 

The research team confirmed that muscle mass does begin to decline from 40 years of age onwards but that the study results suggest that incorporating more fibre into your diet could alter lean body mass, to which muscle is the biggest and the most adaptable.

It turns out people aren't getting enough fiber from their diets. According to Harvard Health, in 2002 the Institute of Medicine advised that adult males up to the age of 50 should consume 38g of fiber a day. After the age of 50, they recommend getting 30 grams per day. 

For women set recommendations were 25g of fiber to be consumed for females up to the age of 50 and 21g after 50 years of age. 

Americans are said to be falling short of this with many individuals only eating 16g of fiber on the daily.

Woman holds spoon of cereal packed with fiber up from a bowl

(Image credit: Getty)

If you are looking for more reason to include more fiber in your diet then take this 2019 study published in The Lancet as another motive. The research which was commissioned by the World Health Organization found from looking at data across 1000 participants that those eating high amounts of fiber had less chance (15-30%) of a cardiovascular related death than those who didn't.

They also discovered that having a diet rich in fiber could reduce the risk of heart disease, type 2 diabetes and colorectal cancer. 

You can add more fiber in your diet by eating foods like lentils and beans, these are great to add to stews and soups. Or various dried fruits are great for getting fiber into your diet such as prunes or figs. 

And you can still enjoy toast in the morning just by swapping your usual loaf of bread for wholegrain, which is high in fiber. You can top up your morning fiber intake even more by smashing an avacado onto your wholegrain toast.

As well as ensuring you eat a recommended amount of fiber to protect your health and increase muscle mass and strength as you age you can also take essential vitamins for your health. 

Starting with the best fish oil supplements can be a good way to maintain a healthy heart and brain as you enter your 40s, a small way to keep your body up to speed, despite things beginning to decline.

Jessica Downey

Jessica is an experienced fitness writer with a passion for running. Her career in journalism began in local news and she holds a Masters in journalism. Jessica has previously written for Runners World, penning news and features on fitness, sportswear and nutrition. 


When she isn't writing up news and features for Fit&Well covering topics ranging from muscle building, to yoga, to female health and so on, she will be outdoors somewhere, testing out the latest fitness equipment and accessories to help others find top products for their own fitness journeys. Her testing pairs up nicely with her love for running. She recently branched out to running 10Ks and is trying to improve her time before moving on to larger races. Jessica also enjoys building on her strength in the gym and is a believer in health and wellness beginning in the kitchen. She shares all of this on her running Instagram account @jessrunshere which she uses for accountability and for connecting with like-minded fitness lovers.