Your diet tends to evolve along with the number of candles on your birthday cake. For example, in your hard-training teens and early 20s, you could probably eat at Taco Bell several times a week and still remain fairly lean. That changes during your 30s and 40s. After turning 50, many people start dropping their calories in response to an ever-slower metabolism.

Makes sense—on the surface, anyway.

While reducing calories may help you maintain your body weight, is lowering your energy intake the best option for overall health? Not necessarily, especially if your calorie cutting involves consuming less protein. Protein supports muscle health and growth, which helps your body stay functional at all ages. It's also what helps support proper tissue health, including hair, teeth, and fingernails. Protein subunits called amino acids are integral components of signaling molecules and represent half of all hormones.

Research suggests that increasing protein intake as you age can support weight management and body-fat reduction. This is due to the enhanced metabolic rate and better satiety that occurs with consuming enough protein.[1,2]

Father Time Does Not Like Muscle, Unfortunately

In your 30s, your muscle mass begins to naturally decline; after 50, this decline only accelerates. However, adequate consumption of protein, paired with resistance training, dramatically decelerates age-related loss in muscle mass and increases strength in individuals of all ages.[3]

As it ages, the human body needs even more protein to meet the same physiological demands. How do you know if you're getting enough protein? The Acceptable Macronutrient Distribution Range (AMDR) for adults ranges from 10-35 percent of total caloric consumption daily.[4]

The World Health Organization, United Nations University, and American Dietary Guidelines recommend approximately 0.8 grams of protein per kilogram of body weight per day for adults. This translates to about 0.36 grams per pound. The Recommended Dietary Allowance (RDA) for adults over the age of 18 is only 46 grams per day for females and 56 grams per day for males.[5,6]

According to these guidelines, a 180-pound (82 kg) adult would only require about 65.6 grams of protein per day. This works out to only about 13 percent of calories based on a 2,000-calorie diet. This falls at the low end of the AMDR range mentioned above.

So why are the RDA recommendations so low? For starters, many of these recommendations have been around for more than 70 years and are based on the minimum protein requirements to avoid malnutrition.[7] For example, if you calculate protein needs using the 10-35 percent range as dictated by the AMDR, then daily protein needs range from 50-175 grams of protein per day based off a standard 2,000-calorie diet.

So, although the acceptable range for adults over the age of 18 is 50-175 grams of protein per day, the current RDA for protein only barely meets this range for the average adult.

What Are the Recommendations for Older Active Adults?

Keep in mind, these recommendations do not reflect changing macronutrient needs associated with age, nor do they consider the additional protein needs for those individuals who exercise regularly.[8,9]

General sports nutrition recommendations for athletes are approximately 1-2 grams per kilogram of body weight per day, or 82-164 grams of protein per day for a 180-pound adult.[10]

Knowing all this, it seems safe to say that older adults could benefit from higher protein intake, especially if they are physically active, including regular exercise.

Do Aging Women Have Different Protein Needs from Aging Men?

The overall need for more protein in later years is even more pronounced in women. Research including more than 300 elderly participants (average age of 72) indicates that women who consume between 0.8-1.2 grams of protein per kilogram of body weight per day tend to have fewer health problems that those consuming less than 0.8 grams per kilogram of body weight per day.[11]

Protein intake is a modifiable risk factor for sarcopenia—loss of muscle mass—in aging individuals. Protein also contributes to enhanced bone density, greater strength, and improved overall health.[11, 15-17] Since osteoporosis a bigger concern for aging women versus men, enhanced bone density and strength would be additionally beneficial on top of maintaining muscle mass and overall health.

Are There Risks Associated With a High-Protein Diet, Particularly for Older Adults?

The primary objection to increased protein in the diet is the concern that the elevated amino acid intake will stress or damage the kidneys.

It's true that individuals with impaired kidney health should avoid excess protein consumption. However, research conducted on healthy individuals with normal kidney function of varying age, sex, and training status does not seem to support the fear that high protein intake will lead to kidney damage.[8,12-14]

In addition, investigations aimed at evaluating fitness, performance, and muscle function in over-50 populations consistently supports an increased intake of protein at 1.0-1.2 grams per kilogram of body weight per day.[5,8]

Furthermore, research indicates that individuals who have acute or chronic diseases may also benefit from a higher intake of protein than the RDA.[8,12] This seems to suggest that even sedentary, non-training older adults may benefit from a higher protein consumption—assuming they have normal kidney function.

What Exactly Does This Mean for You?

It's difficult to pinpoint exactly how much protein any specific individual needs in a day based solely on ranges, which is why aiming for a precise goal (number of grams) of protein each day can be a more productive way to support your body composition goals.

The approximate protein recommendation for a 100-pound person closely reflects the RDA, but since most adult humans weigh more than 100 pounds, their protein intake may have to increase to maintain muscle mass, physical capabilities, or both with age, especially after age 50.

Are Protein Shakes Safe for Older Adults?

Yes. In fact, protein supplementation can provide tremendous benefit to aging individuals who struggle to meet target protein intake levels with whole foods alone.

As we age, reduced appetites can also make it difficult to meet protein goals through diet alone—another reason why it may be necessary to supplement using protein powders and protein shakes.[18]

Which Protein Powder Is Best for Older Adults?

A range of protein supplements can help individuals meet their specific protein needs. Finding a protein supplement that fits your lifestyle and diet takes some effort. But if the alternative to protein supplementation is consistently failing to meet daily protein targets, adding a supplement is highly advised.

When searching for supplements, seek reputable brands with ingredient lists that are short and understandable. You should be able to recognize and understand what a protein powder is made of.

The source of a given protein powder can affect its effectiveness and cost. Whey protein, for example, is derived from milk, and a large number of research trials have demonstrated whey's safety and effectiveness.[19]

Protein supplement flavors, textures, and pricing are also important factors to consider.

References

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2. Halton, T. L., & Hu, F. B. (2004). The effects of high protein diets on thermogenesis, satiety and weight loss: a critical review. Journal of the American College of Nutrition, 23(5), 373-385.
3. Campbell, W. W., & Leidy, H. J. (2007). Dietary protein and resistance training effects on muscle and body composition in older persons. Journal of the American College of Nutrition, 26(6), 696S-703S.
4. Rafii, M., Chapman, K., Elango, R., Campbell, W. W., Ball, R. O., Pencharz, P. B., & Courtney-Martin, G. (2015). Dietary Protein Requirement of Men> 65 Years Old Determined by the Indicator Amino Acid Oxidation Technique Is Higher than the Current Estimated Average Requirement, 2. The Journal of Nutrition, 146(4), 681-687.
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8. Bauer, J., Biolo, G., Cederholm, T., Cesari, M., Cruz-Jentoft, A. J., Morley, J. E., ... & Visvanathan, R. (2013). Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. Journal of the American Medical Directors Association, 14(8), 542-559.
9. Campbell, W. W., Trappe, T. A., Wolfe, R. R., & Evans, W. J. (2001). The recommended dietary allowance for protein may not be adequate for older people to maintain skeletal muscle. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, 56(6), M373-M380.
10. Thomas, D. T., Erdman, K. A., & Burke, L. M. (2016). American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance. Medicine and Science in Sports and Exercise, 48(3), 543-568.
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12. Deutz, N. E., Bauer, J. M., Barazzoni, R., Biolo, G., Boirie, Y., Bosy-Westphal, A., ... & Singer, P. (2014). Protein intake and exercise for optimal muscle function with aging: recommendations from the ESPEN Expert Group. Clinical Nutrition, 33(6), 929-936.
13. Antonio, J., Ellerbroek, A., Silver, T., Orris, S., Scheiner, M., Gonzalez, A., & Peacock, C. A. (2015). A high protein diet (3.4 g/kg/d) combined with a heavy resistance training program improves body composition in healthy trained men and women–a follow-up investigation. Journal of the International Society of Sports Nutrition, 12(1), 39.
14. Antonio, J., Peacock, C. A., Ellerbroek, A., Fromhoff, B., & Silver, T. (2014). The effects of consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals. Journal of the International Society of Sports Nutrition, 11(1), 19.
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16. Kerstetter, J. E., Looker, A. C., & Insogna, K. L. (2000). Low dietary protein and low bone density. Calcified Tissue International, 66(4), 313-313.
17. Scott, D., Blizzard, L., Fell, J., Giles, G., & Jones, G. (2010). Associations between dietary nutrient intake and muscle mass and strength in community‐dwelling older adults: the Tasmanian Older Adult Cohort study. Journal of the American Geriatrics Society, 58(11), 2129-2134.
18. Pilgrim, A., Robinson, S., Sayer, A. A., & Roberts, H. (2015). An overview of appetite decline in older people. Nursing Older People, 27(5), 29.
19. Keri Marshall, N. D. (2004). Therapeutic applications of whey protein. Alternative Medicine Review, 9(2), 136-156.