As a person ages, body fat rises and muscle mass decreases. Maintaining or increasing muscle mass to combat age related sarcopenia is paramount to healthy aging.
Maintaining or increasing muscle mass not only improves the performance of day-to-day activities, it can increase athletic ability in the active adult. In a study of dietary protein adequacy and resistance training performed by Campbell et al, men consumed the RDA for protein during a 12-week period of resistance training.2 This study indicated that the amount of protein intake was only marginally adequate for muscle hypertrophy. This suggests that standard protein amounts for the older adult during training may not be adequate.
What about the type of protein consumed? Is that a factor?
Proteins can come from a variety of sources: meats, such as beef, poultry, pork or fish; dairy products such as yogurt, eggs and milk; or non-meat sources such as beans, soy, tempeh, etc. One study attempted to address the issue of types of protein and the effect on resistance training in the older adult. This may be important since some older adults may be on a tighter budget, may have sensory changes in taste and smell as they age or have dental issues affecting their ability to chew. When training an older adult, just telling him or her to eat a steak for protein may present a financial hardship or a physical challenge. So discussing food and nutrition in a non-condescending manner to identify alternate food choices that can provide an adequate source of protein is important.
In the same study performed by Campbell et al, the effects of consuming a meat-containing diet versus a meat-free diet on whole body composition and skeletal muscle size in older males was evaluated.2 During 12 weeks of resistance training, protein intake was about 1.0g/kg (125% RDA) for the meat-containing diet and 0.8g/kg (100% RDA) for the meat free diet. Initial results showed a 10% to 38% increase in muscle strength among the participants with no significant differences between the two groups. However, over time with training, the study showed that ingestion of meat-containing diet did promote somewhat larger gains in skeletal muscle when compared to the meat-free diet.
Essentially, muscle protein is affected by protein intake no matter what the source. However, high-quality dietary protein intake may increase protein synthesis by increasing amino acid availability to the muscles.3 High quality proteins are often in the meat categories. Eggs, in particular, are one of the best choices of protein; they are relatively inexpensive and can be prepared in many ways. Eggs can also be added to other foods to boost protein content. Studies have also dispelled the myth that eggs are bad for you. It’s acceptable to eat at least two eggs a day unless strictly advised otherwise by a physician. Of course, every sort of egg substitute is available now without the cholesterol, but with all the protein.
One caveat: Sometimes the older adult is fearful of eating too much protein fearing high cholesterol levels, heart disease or kidney damage. There is a lot of information available today on low carb/high protein diets. There are claims that metabolizing large amounts of protein can lead to an increased workload on the kidneys causing damage. This has not proven to be definitive, except perhaps in cases of someone with underlying kidney disease. Individuals with kidney damage must be monitored by a doctor not only for the amounts of protein that can be ingested but the amounts of water intake. Those clients should not be trained without checking first with their healthcare provider.
So educating the person on these facts is imperative if you have reason to think he or she can’t or won’t eat enough protein to promote muscle growth.
Is there an exact amount an older adult should be getting beyond the RDA’s recommendations?
That is the million-dollar question. It does appear that as a person ages, more protein is needed to avoid sarcopenia as much as possible. How much over the RDA recommended amount is open to debate, however. Many studies have touched on ingesting 125% to 150% of the RDA recommendations to improve amino acid synthesis and muscle hypertrophy in older adults.
When training the older adult, it’s essential they understand the nutrient needs of aging and not just as it relates to training. Protein does more than prevent sarcopenia. It helps in healing, fall prevention, immune function, glucose control and bone health. It also can help decrease whole body fat as muscle is highly metabolic and burns fat even when at rest. According to Heymsfield et al, when at rest, skeletal muscle consumes 54.4 kJ/kg (13.0 kcal/kg) per day.4 This is greater than that consumed by both adipose tissue (fat) at 18.8 kJ/kg (4.5 kcal/kg), and bone at 9.6 kJ/kg (2.3 kcal/kg).4
Encouraging clients in this age group to keep a diet diary can be a very important tool, as it allows older adults to monitor the amount of protein they are ingesting as well as the different types available.
Educating clients on age related changes in muscles and the need to increase their intake is essential. Overall, the older adult can prevent the ravages of muscle loss by eating enough high quality protein and leading a healthy lifestyle as well as performing resistance training. A long life of good health can be had.
1. Dreyer HC, Volpi E; Role of protein and amino acids in the pathophysiology and treatment of sarcopenia. J Am Coll Nutr 24:140S-145S, 2005.
1A. Roubenoff R, Hughes VA: Sarcopenia; current concepts. J Gerontol Biol Sci Med Sci 55:M716-M724, 2000.
2. Campbell WW, Barton ML, Jr, Cyr-Campbell D, Davey SL, Beard JL, Parise G, Evans WJ; Effects of an omnivorous diet compared with a lactoovovegetarian diet on resistance-training-induced changes in body composition and skeletal muscle in older men. AM J Clin Nutr 70:1032-1039, 1999.
2A. Fujita S, Volpi E: Amino acids and muscle loss with aging. J. Nutr. January 2006 vol. 136 no. 1 277S-280S.
3. Motil KJ, Mathews DE, Bier DM, Burke JF, Munroe HN, Young VR. Whole-body leucine and lysine metabolism: response to dietary protein intake in young men. Am J Physiol Endocrinol Metlab 1981;240:E712-21.
4. Heymsfield, SB; Gallagher, D; Kotler, DP; Wang, Z; Allison, DB; Heshka, S (2002). “Body-size dependence of resting energy expenditure can be attributed to nonenergetic homogeneity of fat-free mass”. American Journal of Physiology – Endocrinology and Metabolism 282 (1): E132-E138. PMID 11739093. http://ajpendo.physiology.org/cgi/reprint/282/1/E132.
About the Author
Chiffon Okuda is a graduate of Muhlenburg School of Nursing in Plainfield, NJ, and holds a BAAS from the University of North Texas in Health Promotion and Community Services. She has been a registered nurse for over 20 years, specializing in the older adult and currently works for a large public hospital as a geriatric case Manager. She is an NFPT-certified personal trainer, fitness nutrition specialist, and a SECA (Strength, Endurance,Combat, Agility) Senior Group Kettlebell Instructor, holding classes at a local recreation center as well as providing private personal training.