Protein

Emerging evidence indicates that the role of amino acids from dietary protein goes beyond the basics of growth and repair. Including more protein in the diet may play a beneficial role in heart health, type 2 diabetes and bone health.

Lean beef is an excellent source of high quality, complete protein and a part of Eating Well with Canada’s Food Guide.

Heart Health

Higher protein intakes within the Dietary Reference Intake (DRI) guidelines (up to 35% of energy) do not appear to increase cardiovascular disease.¹

In fact, researchers have found that higher protein intakes may help lower risk of cardiovascular disease. Studies have shown that high-protein, low-carbohydrate diets reduce blood triglyceride levels, increase HDL cholesterol, increase LDL particle size and reduce blood pressure.²

Controlled clinical trials have found improvements in blood lipid profiles when carbohydrates were replaced with protein in both hypercholesterolimic and normolipidemic individuals.^3,4,5

High protein, low carbohydrate diets seem to be especially useful for individuals with the dyslipidemia associated with metabolic syndrome, a risk factor for cardiovascular disease.²

Studies have also found a significant relationship between higher protein intakes and a lower risk of hypertension and cardiovascular disease.⁶ Although the exact mechanism by which protein impacts blood pressure is not definitive, evidence that protein decreases blood pressure is consistent.²

1. Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrates, Fibre, Fat, Protein and Amino Acids (Macronutrients). National Academy Press, Washington, 2002.

2. Layman et al. Am J Clin Nutr 2008; 87(Suppl):1571-5S.

3. Wolfe BM and Giovannetti PM. Metabolism, 1992; 40:338-43.

4. Wolfe BM and Giovannetti PM. Clin Invest Med, 1992;22(4)140-8.

5. Wolfe BM and Piché LA. Atherosclerosis, 1994; 109:71 (abstr.)

6. HU FB. Am J Clin Nutr 2005; 82(suppl):S242-7.

Diabetes

Current evidence indicates that reducing carbohydrate and increasing protein intakes may be an effective and healthy dietary approach for reducing the risk of diabetes.¹

Higher protein diets have been found to be better for weight management and glycemic control than high-carbohydrate, low-fat diets – for individuals with or without type 2 diabetes.¹

There is evidence that increasing protein intakes can facilitate weight loss in part because of impact on satiety. Weight loss has repeatedly been shown to improve blood glucose regulation in people with and without type 2 diabetes. Overweight is a major risk factor for type 2 diabetes.¹

Clinical trials show that diets that are rich in lean protein and lower in carbohydrates can help improve glycemic control including reductions in post-prandial glucose response, insulin response and glycated hemoglobin percentage (HbA1c).^1,2,3,4

Although diets need to be individualized, a higher protein diet, which improves outcomes for weight loss, blood lipid reduction and glycemic regulation, may be a practical and effective option.

1. Layman et al. Am J Clin Nutr 2008; 87(Suppl):1571-5S.

2. Layman DK et al. J Nutr, 2003; 133(2):405-10.

3. Farnsworth et al. Am J Clin Nutr, 2003; 78(1):31-9.

4. Parker B et al. Diabetes Care, 2002; 25:425-30.

Bone Health

Bone strength and density is highly dependent on maintenance of adequate muscle mass and function. In turn, muscle strength and function is dependent on adequate intake of high-quality protein.^1,2 Along with muscle-promoting benefits, protein is also an integral part of bone matrix and a daily supply of protein is required for healthy bone maintenance.

Optimal protein intake to enhance muscle protein synthesis and reduce progressive loss of muscle that comes with age (sarcopenia) is likely higher than current recommendations; there is general agreement that a moderate increase of protein above the Recommended Dietary Allowance (.8g/kg/d) would be beneficial.⁴

Research shows that type, as well as amount, of protein is an important consideration for promotion of muscle protein synthesis. High-quality protein, providing essential amino acids (especially leucine), appear to be better able to stimulate muscle synthesis.³ For example, a recent study found that consuming four ounces of lean beef acutely increased muscle protein synthesis by 50% in both young and elderly volunteers.⁵

Sarcopenia is a complex condition associated with loss of muscle mass and strength as adults age. Advanced sarcopenia can be debilitating and is associated with increased frailty, decreased stamina and ability to function in daily living, and increased probability of falls and bone fractures.

Although there is no single cause, likely contributors are a poor diet with insufficient protein intake and a sedentary lifestyle.³

Provide guidance on how to select and prepare lean meats and alternatives and lower fat milk products within Canada’s Food Guide.

NOTE: Assessment of renal function also tends to decline with age and should be assessed prior to recommending high protein intakes among the elderly.³

1. Heaney RP and Layman DK. AM J Clin Nutr 2008; 87(suppl):1567S-70S.

2. Wolfe R. Am J Clin Nutr, 2006; 84:475-482.

3. Paddon-Jones D et al. Am J Clin Nutr, 2008; 87(suppl):1562S-6S.

4. Campbell WW et al. J Gerontol A Biol Sci Med Sci 2001;56:<373-80.

5. Symons TB et al. Am J Clin Nutr, 2007;86:451-6.

How Much Protein?

Current Dietary Reference Intake (DRI) guidelines state that adults can safely consume 10 to 35% of daily calories from protein.¹ It is generally difficult to consume a typical diet with greater than 35% of energy as protein.²

According to the Canadian Community Health Survey 2.2, adult intakes average 16.8% of calories from protein; this intake is at the lower end of the DRI.³

Health professionals can recommend clients include additional lean protein (up to 35% of energy) as part of a balanced healthy diet.

Special Considerations
The DRI report notes that vegans who restrict their diets to plant foods only may be at risk of not getting adequate amounts of certain indispensable amino acids.¹ However, lacto-ovo vegetarian diets that include high quality protein from milk and eggs and vegetarian diets that include complementary mixtures of plant proteins can provide adequate intakes of all indispensable amino acids.

1. Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrates, Fibre, Fat, Protein and Amino Acids (Macronutrients). National Academy Press, Washington, 2002.

2. Wilkinson DL and McCargar L. Best Practice and Clinical Gastroenterology, 2004; 18(6):1031-47.

3. Garriguet D. 2006. Ottawa: Health Statistics Division, Statistics Canada, 2006. Available online (accessed July 10, 2025).