By Holly Swee, Registered Dietician & Licensed Nutritionist, South Dakota Beef Council
Adequate protein is essential for good nutrition throughout the lifespan. While there is no single
identifiable cause of sarcopenia, a condition associated with a loss of muscle mass and strength in
seniors, insufficient protein intake may be a key contributor. Since loss of muscle can decrease stamina, lessen the ability to perform daily tasks, and increase the risk of falls and bone fractures, the prevention of sarcopenia is becoming an increasingly important public health issue.
A recent study published in the Journal of the Academy of Nutrition and Dietetics (To access this study, go to http://bit.ly/1qx42wX
) takes a closer look at protein intake among older U.S. adults. Food intake tends to decline with and current dietary recommendations emphasize a shift to more plant-based diets, which could be cause for concern in regards to adequate protein consumption.
In the newest study, “Characterization of Dietary Protein among Older Adults in the United States”,
researchers with California Polytechnic University used data from the 2005-06 National Health and
Nutrition Examination Survey to quantify protein intake and determine adequacy of protein in the diets of U.S. adults.
Typical protein intakes were considerably lower than if a USDA food pattern was followed. As
expected, older adults had lower than average protein intake and a higher incidence of inadequate
intake versus younger adults.
Protein intake was also notably lower in women in comparison to men. Protein from animal sources
contributed more than 60% of protein sources, on average, with dairy as the largest contributor,
followed by poultry and beef. Specifically, beef provided approximately 14% of total protein intake of all adults (19+ yrs). Using logistic regression analyses, a higher proportion of total protein intake from animal foods predicted a higher likelihood of meeting the protein RDA, whereas a higher proportion from plant foods was a negative predictor.
Several previous studies have produced similar findings. A 2012 cross-sectional study published in the British Journal of Nutrition suggests that exercise combined with adequate high-quality protein
preserves muscle in adults over 50. In this study, obese subjects were also included and they required a level of protein that is above the RDA. A 2009 Current Opinion in Clinical Nutrition and Metabolic Care article about protein and sarcopenia found that consuming a moderate amount of high-quality protein at each meal can stimulate the process of muscle building and protect against sarcopenia.
In the current study, the results prompted the authors to suggest that a shift away from animal sources of protein would have a negative impact on overall protein intake, increasing the risk of sarcopenia. To minimize the negative impact of high dietary fat, they recommend greater focus on leaner and lower fat animal protein options.
Holly Swee is a Registered Dietician and a Licensed Nutritionist with the South Dakota Beef Council.