Muscle loss and protein needs in older adults

It's not your imagination: it is harder to gain — or just maintain — muscle after middle age. Aging brings many changes to the body. One such change is muscle loss. Adults who don't engage in regular strength training can lose 4 to 6 pounds of muscle per decade.

The technical term for age-related muscle loss is sarcopenia, and it affects nearly 50% of adults above the age of 80. While sarcopenia is a natural part of aging, it can impact quality of life by increasing the risk of frailty, disability, loss of independence, and even death.

To combat sarcopenia, you can build muscle through strength training. Building muscle requires protein, so when you're aiming to increase muscle mass, your body needs more protein. Increasing dietary protein intake can support muscle repair and growth.

Getting more protein from your diet

The amount of protein a person should consume each day depends on factors such as height, weight, age, sex, and activity level. You can use this USDA calculator to find your daily recommended protein intake. For the average adult, the Recommended Dietary Allowance (RDA) of protein is 0.36 grams per pound of body weight. For a person who weighs 165 pounds, for example, that comes to 60 grams of protein per day.

Unfortunately, many older adults aren't meeting their daily protein needs. A study published in the Journal of Nutrition, Health & Aging that looked at the diets of nearly 12,000 individuals ages 51 and older found that approximately 46% didn't meet daily protein recommendations. Lower protein intake makes it more challenging to build muscle mass.

While consuming enough protein to support muscle gains is important for overall health, too much protein can also lead to health issues. Consuming very high amounts of protein per day — anything over 0.907 grams per pound; or about 150 grams per day for a 165-pound person — can be harmful. More than that can cause dehydration or aggravate kidney problems for individuals with pre-existing kidney conditions such as chronic kidney disease or a history of kidney stones.

A wide variety of foods, both plant- and meat-based, are high in protein. These include beans, peas, and lentils; nuts and seeds; lean meats; fish; dairy products; and soy products. Incorporating more of these foods into your diet is the easiest way to up your protein intake.

In addition to eating high-protein food sources, when you consume protein is also important. Experts recommend spreading protein consumption throughout the day, with good protein sources at each meal.

Can protein supplements help?

While the best source of protein in your diet is whole foods, some older adults who cannot get adequate protein through food alone may benefit from supplementation. To decide if you should add protein supplements to your diet, consult with your doctor.

Many people find protein supplements such as protein powders an attractive and easy solution to meeting their daily protein needs. Over-the-counter protein powder supplements have become increasingly popular in the United States and are a multibillion-dollar industry.

One reason may be that protein powders are convenient. They can be easily added to oatmeal or smoothies, or simply mixed into a glass of water. They come with convenient scoopers to help you see exactly how much protein you are adding. Always check the label to find the amount of protein per serving, as this varies by brand of supplement.

However, there are some concerns to be aware of when consuming protein supplements. Protein powders are classified as dietary supplements and are not regulated as strictly as food or medicine. In addition, the sugar content of protein powders can be vary depending on the brand; some brands may have as much as 23 grams per scoop. In addition, whey- or casein-based protein powders can cause digestive discomfort in some individuals.

Types of protein powders

There are three main types of protein powders: whey, casein, and plant-based protein powders. Both whey and casein are animal-based protein powders, made from dairy. Plant-based protein powders are usually a combination of protein derived from wheat, pea, hemp, or soy products.

Of the three, research suggests that whey protein is particularly effective for building muscle in older adults, more so than either plant-based proteins or casein.

For individuals who are avoiding dairy, plant-based protein powder options like soy isolate protein can also be beneficial. These generally have a lower amino acid profile and reduced bioavailability compared to animal-based proteins. Bioavailability is the measure of how much and how quickly a substance, such as a nutrient or drug, is absorbed and becomes available for use in the body. Vegan protein powders made from peas or brown rice are also suitable alternatives to dairy-based protein supplements.

The importance of resistance and strength training for preserving muscle mass

While protein is important for building muscle mass, it should be combined with strength training to combat sarcopenia. Research shows that supplementing the diet with protein plus a regimen of heavy resistance exercise leads to the most improvement in muscle mass and strength in healthy older adults. Together, the two approaches can significantly aid muscle growth in older adults.