Protein is one of the three macronutrients that your body needs to function properlyContinue reading
Many people, including some researchers, have differing opinions when it comes to the amount of daily protein your body actually needs. The numbers also vary depending on whether you’re a strength or an endurance athlete. Additional factors like age and the number of days you’re hitting the gym will also play a role in your intake.
Do you need the suggested RDA of 0.8 grams/kg/day or is it more in line with 1-2 gram/kg/day? The answer may depend partly on the volume of work you’re doing in daily workouts. Here is what some of the research has shown regarding daily protein intake.
Research Shows a Higher Need for Protein Intake
Back in the 1970’s and 1980’s, a few published studies suggested exercise might actually cause significant changes in protein metabolism. One such study done at the USDA HNRC on Aging at Tufts University in 1988. I was actually one of the ‘”young” research subject for this particular study. The study by Meredith and colleagues looked at the protein needs of six young (26.8 +/- 1.2 yr) and six middle-aged (52.0 +/- 1.9 year) endurance-trained men. All of the subjects consumed either 0.6, 0.9, or 1.2 grams/kg/day of high-quality protein over three separate 10-day periods. All subjects maintained their training and a constant body weight. The results of the study estimated that protein requirement was 0.94 +/- 0.05 grams/kg/day for the 12 men, with no effect of age. The data from this study showed greater daily protein needs than the current Recommended Dietary Allowance of 0.8 g/kg/day.
Additional Research on Daily Protein
Several studies based on data collected from individuals engaged in vigorous aerobic exercise, on a regular basis, demonstrated higher daily protein needs more in line with 1.1 to 1.4 grams/kg/day. This by the way is about 38%-75% above the current RDA range. Various research groups have reported the optimal intake should be more in line with a protein range of 1.5 to 1.8 grams/kg/day; about 88% to 125% above the RDA.
A research paper published by Roger Fielding and his colleague cited “current recommended intakes of daily protein for strength and endurance athletes are 1.6 to 1.7 g/kg and 1.2 to 1.4 g/kg per day, respectively. They went on to mention that most athletes get enough protein in their diet. Where most typically get things wrong is with “the timing and nutritional content of the post-exercise meal, (is) often overlooked.”
Current recommended protein intake could actually limit muscle growth. Dietary protein needs according to Lemon and colleagues, for physically active individuals, has been debated for centuries. The RDA guidelines are not going to change any time soon. The evidence supports a higher daily protein intake for individuals involved in strenuous physical activity, such as strength training. More in line with 1.1 to 1.8 grams/kg/day, in order to effectively increase lean muscle tissue. If you are not involved in regular exercise, the RDA of 0.8 grams/kg/day will suffice.
1. Lemon, PWR (2000). Protein metabolism during exercise. Exercise and Sport Science, 19-27.
2. Evans WJ et al. (1983). Protein metabolism and endurance exercise Phys Sports Med 11:63-72.
3. Friedman JE et al. (1989). Effect of chronic endurance exercise on the retention of dietary protein. Int J Sports Med 10:118-123.
4. Tarnoplosky MA (1992) et al. Evaluation of protein requirements for trained strength athletes. J Applied Physiology 73:1986-1995.
5. Lemon PWR, Tarnoplosky MA et al. (1992). Protein requirements and muscle mass/strength changes during intensive training in novice bodybuilders. J Applied Physiology 73:767-775.
6. Fielding, R, et al. (2002). What are the dietary protein requirements of physically active individuals? New evidence on the effects of exercise on protein utilization during post-exercise recovery. Nutr Clin Care, 5(4):191-6.
Research has shown that it’s important to eat protein at each meal. Many Americans eat a diet that consists of little to no protein for breakfast. This is followed up with a small portion of protein at lunch and an overabundance of protein at dinner. In fact, as long as they get their recommended dietary allowance of about 60 grams, it’s all good, right? Not according to research from a team of scientists led by muscle metabolism expert Doug Paddon-Jones, PhD, of the University of Texas Medical Branch at Galveston (UTMB). This research shows that the typical cereal or carbohydrate-dominated breakfast, a sandwich or salad at lunch and overly large serving of meat/protein for dinner may not provide the best metabolic environment to promote healthy aging and maintenance of muscle size and strength.
Age-related conditions such as osteoporosis (bone weakening) and sarcopenia (muscle loss) do not develop all of a sudden. The researchers believe rather, that they are gradual processes triggered by poor lifestyle habits starting in early middle age.
Review of Research
The UTMB researchers provided volunteers with a generous daily dose of 90 grams of protein a day; consistent with the average amount currently consumed by healthy adults in the U.S. Very active individuals may benefit from a slightly higher protein intake. For the majority of adults, additional protein will likely have a diminishing positive effect on muscle metabolism says the researchers. Just as important, any less may fail to provide support for optimal muscle metabolism.
When study volunteers consumed the evenly distributed protein meals, their 24-hour muscle protein synthesis was 25 percent greater than subjects who ate according to the skewed protein distribution pattern.
An Eating Strategy for Protein
“Usually, we eat very little protein at breakfast, a bit more at lunch and then consume a large amount at night. “So we’re not taking enough protein on board for efficient muscle building and repair during the day, and at night we’re often taking in more than we can use, says Paddon-Jones.”
A more efficient eating strategy for building muscle and controlling total caloric intake would be to shift some of the extra protein consumed at dinner to lunch and breakfast.
“You don’t have to eat massive amounts of protein to maximize muscle synthesis. You just have to be a little more thoughtful with how you apportion it,” Paddon-Jones said. “For breakfast consider replacing some carbohydrate, particularly the simple sugars, with high-quality protein. Throw in an egg, a glass of milk, yogurt or add a handful of nuts to get closer to 30 grams of protein. Try doing something similar to get to 30 grams for lunch, and then moderate the amount of protein for dinner. Do this, and over the course of the day you will likely spend much more time synthesizing muscle protein.” Eat healthy and stay strong with Jefit.
Madonna M. Mamerow, Joni A. Mettler, Kirk L. English, Shanon L. Casperson, Emily Arentson-Lantz, Melinda Sheffield-Moore, Donald K. Layman, and Douglas Paddon-Jones, Dietary Protein Distribution Positively Influences 24-h Muscle Protein Synthesis in Healthy Adults, J Nutr. 2014 Jun; 144(6): 876–880. Published online 2014 Jan 29. doi: 10.3945/jn.113.185280