Protein Part I: How Much Protein Do We Need?
By Cristina Sutter, SportMedBC RunWalk Dietitian
Scientists have some new answers to the popular question of how much protein we need to build muscle. Researchers are now using a new method of estimating protein requirement known as IAAO (Indicator amino acid oxidation), which estimates our protein needs at 1.2g protein per KG of body weight. This amount is 40-50% higher than the current Canadian protein requirement advised by the Recommended Dietary Allowance (RDA). The RDA was calculated using an imperfect method called nitrogen balance, which is known to underestimate our protein needs. Additionally, the RDA level was designed to avoid overt deficiencies and new research is demonstrating that this underestimates the optimal amount of protein needed for sustaining and building muscle mass. We now know that our Canadian protein recommendations fall short of promoting optimal muscle mass.
Both young and older women tend to consume less protein than their male counterparts. For an average 50 year old woman who weighs 154 lbs, she needs 1.2g protein (X 70kg) = 84g protein per day to maintain and build muscle. She can get this much protein in one day from:
- 2 eggs (16g protein)
- 1 cup milk (8g protein)
- 1 can tuna (30g protein)
- 100g chicken or 2/3 of a chicken breast (27g protein)
- ½ cup yogurt (4g protein)
Unfortunately, we lose muscle mass and function as we age, which limits our mobility in our golden years. A study published in the American Journal of Clinical Nutrition found that we can prevent and reverse this aging process with resistance exercise and including a serving of high quality protein in all our meals. Older adults need more protein to stimulate muscle building and prevent muscle loss than younger folks who build muscle more efficiently after exercise. This study showed that older adults can protect and build their muscle mass by consuming higher amounts of essential amino acids (in particular, leucine) at their meals. The only complete sources of essential amino acids are dairy, eggs, fish, meat, poultry, soy and spirulina seaweed. Interestingly, this is where meat and dairy outperform vegetarian alternatives, and research supports dairy protein as enhancing fat loss and building muscle mass.
Beyond its muscle building benefits, we know that including a serving of protein at every meal keeps us full for longer and reduces hunger and cravings later in the day. Dietitians agree that a diet that includes small, frequent meals made up of vegetables, fruits, protein, dairy and whole grains help us stay satisfied and achieve a healthy weight without feeling hungry. Whether you want to build muscle, lose fat, or delay aging, choose a balanced diet that includes high quality protein sources every day.
Protein part two comes next week!
Cristina Sutter is a Private Practice Sport Dietitian at Optimal Performance Clinic in Vancouver. For more information, visit cristinasutter.ca.