Protein is a nutrient darling and for good reason. Protein is essential for muscle synthesis, immunity, blood formation, bone health, is a source of energy and promotes weight loss.1
According to experts, Canadians would do their health wonders by increasing their protein intake from the current 17% daily energy intake to 30%.2 When combined with an active lifestyle, this level of protein intake will have the following benefits:
Maintain Muscle and Muscle Strength
As early as 40 years of age, we lose lean body mass – or muscle – with a simultaneous increase in fat.3 The loss of muscle is paralleled by reductions in muscle strength.4 This situation is concerning because loss of muscle strength leads to loss of muscle function which predisposes older men and women to falls and fractures that can significantly affect quality of life. Physical inactivity, as a result of injury, perpetuates the loss of muscle mass.
For optimal muscle synthesis, all amino acids need to be present simultaneously – a complete protein food or complimentary combination of incomplete protein foods. Certain amino acids cannot be produced by the body and therefore must come from the diet.5 Whole foods from animal sources like beef, pork, fish, eggs, and poultry contain all the amino acids our body cannot make.
Maintaining Bone Health
Like muscle, our bones are dynamic – constantly being broken down and synthesized. Studies have demonstrated that higher protein intakes combined with recommended calcium consumption enhance calcium absorption.6 Lower protein diets (< 0.8 g/kg/day) actually compromise bone’s ability to repair and recover from fractures, whereas diets moderate in protein (1-1.5 g/kg/day) are associated with normal calcium metabolism, greater bone mass, and fewer fractures when calcium intakes are adequate. Increasing protein intake to this recommended level would maintain normal calcium metabolism and nitrogen balance without affecting renal function. 6 This relationship is significant and reinforces the integration of muscle and bone for healthy aging.
In the context of longevity, living well, and staying healthy, the role of high quality protein foods as nutrient rich sources of essential micronutrients cannot be overstated.7 Iron, calcium, zinc, B vitamins, and antioxidants such as vitamin E are found in animal products like meat, dairy, poultry, and seafood. With the need for many Canadians to reduce the amount of food they eat for weight management, choosing high quality protein foods takes on greater importance. That is, meal patterns should consider protein quality – foods containing the indispensable amino acids – and protein density – the amount of protein relative to the calories – and the micronutrients of the food choices.
Routine consumption of high quality protein foods such as beef, pork, fish, eggs, and poultry, distributed evenly throughout the day – approximately 25 to 30 grams per meal – is the ideal. From a practical perspective, a diet based on whole foods, complemented with an active lifestyle, provides a feasible and reasonable approach to healthy living.
What is the protein and weight loss connection?, 2019, thinkbeef.ca/what-is-the-protein-and-weight-loss-connection.
Phillips SM et al. Protein “requirements” beyond the RDA: implications for optimizing health. Appl Physiol Nutr Metab, 2016, 41(5): 565-72.
St-Onge MP. Relationship between body composition changes and changes in physical function and metabolic risk factors in aging. Curr Opin Clin Nutr Metab Care. 2005; 8:523–8.
Kalyani R et al. Age-related and disease-related muscle loss: the effect of diabetes, obesity, and other diseases. Lancet Diabetes Endocrinol. 2014 Oct; 2(10): 819–829.
Wolfe R et al. Protein quality as determined by the Digestible Indispensable Amino Acid Score: evaluation of factors underlying the calculation. Nutr Rev. 2016 Sep; 74(9): 584-99.
Gaffney‐Stomberg E et al. Increasing dietary protein requirements in elderly people for optimal muscle and bone health. Journal of the American Geriatrics Society, 2009; 57(6): 1073-1079.
Asp ML et al. Dietary protein and beef consumption predict for markers of muscle mass and nutrition status in older adults. J Nutr Health Aging. 2012; 16(9):784-90.