By Paulette Lambert, RD, CDE Director of Nutrition California Health & Longevity Institute
Protein is a hot topic in nutrition and the marketing campaigns of food products, generating myriad “high-protein” foods in the marketplace as well as continued questions from consumers as to dietary recommendations. Despite the continued push among food producers to create protein-rich offerings, according to the US Department of Health and Human Services Dietary Guidelines for Americans, the reality is that “inadequate protein in the US population is rare.”1
So what should we know about the role protein should play in our diet? Do we really need as much as many food companies would have us believe?
For years the recommended daily allowance (RDA) has been 0.36 grams (g) of protein per pound of body weight (a woman weighing 125 pounds, for example, would require 45 g of protein per day).2 Current protein standards, however, are based on studies conducted with younger adults, many of which were completed 50 years ago. Now, with increased interest among the aging adult population in updated guidelines that are appropriately specific to age and weight, recommendations are being reviewed and revised.
In the past year, the International Osteoporosis Foundation and the European Society for Clinical Nutrition and Metabolism reviewed the latest research and have come to this conclusion: to preserve muscle mass and stay healthy longer, older adults (60-plus years) should increase their protein intake from 0.36 to 0.54 g per pound of body weight.3,4
Age-appropriate recommendations are important because we lose muscle mass as we age—1 percent per year after age 30 and twice that much by age 70—a process known in medical terminology as sarcopenia. Muscle mass not only makes you look fit but it is critical for movement, everything from basic functions like walking up and down the stairs and carrying grocery bags to exercise and other desired recreational pursuits. Loss of muscle mass can limit your lifestyle and can cause fragility in old age.
Research into the full range of benefits that sufficient protein provides is ongoing. The Women’s Health Initiative observational study, which followed 24,000 women age 65 or older for three years, concluded that the women consuming 0.54 g of protein per pound of body weight daily resulted in 32 percent less likelihood of becoming frail and was related to an increase in muscle strength.5 Some short-term studies have shown that having a consistent intake of protein throughout the day, at each meal, can make the difference in how much muscle synthesis occurs; those who had adequate protein throughout the day did better than those who had little and then a lot at one time.6 Other research showed that getting more than the recommended daily amount of 0.54 g per pound did not result in more muscle gain or an increase in strength.7
Additional research is also reflecting the role protein can play in weight loss. Preliminary studies show that adequate protein intake of 0.36 to 0.54 g had a modest effect on decreasing the appetite, but a high-protein diet resulted in no greater weight loss than one including just adequate protein when both diets included the same number of calories. Other studies have investigated concerns that too much protein can cause cancer, bone loss, or kidney disease; at this point research suggests that that is not the case.8,9,10,11
We are clearly still learning from ongoing research about all the different ways that protein intake can affect our health. As studies continue to deliver additional information, the following guidelines can serve as a basic plan for incorporating protein in our diets.
And remember, though protein intake plays a big role in building necessary muscle mass as you age, it is critical to incorporate strength training into your exercise routine (three times per week); diet alone will not ensure that you maintain the muscle strength you need to live a healthy, active life.
Tags: Nutritional Know-How