More Is Not More
The study, led by Douglas Paddon-Jones, PhD, and reported in the September 2009 issue of the Journal of the American Dietetic Association, compared muscle synthesis (formation) and anabolic efficiency in response to meals with moderate and high amounts protein in 17 young (average age 34) and 17 old (average 68 years) volunteers. The subjects were healthy and physically active. Both meals were made up of gently warmed precooked ground beef. One meal contained 30 grams of protein (the rough equivalent of 4 ounces of chicken, fish, dairy, soy, or, in this case, lean beef). The other meal contained three times as much protein, 12 ounces of lean beef and 90 grams of protein.
“We recently demonstrated that a single moderate-size serving of a protein rich food (4 oz. lean beef) acutely increased muscle protein synthesis above fasting values by 50% in both young and elderly individuals,” the researchers wrote in introducing the study. “A 4 oz. serving of 90% lean beef (220 calories) contains approximately 30 g of protein, 10 g of essential amino acids (EAA) and represents 50% of the Recommended Dietary Allowance for a 75-kg [165 lbs] individual.”
The question they set out to answer was whether more protein would stimulate additional muscle building. “[We] sought to determine whether a three-fold larger protein and energy-rich meal (12 oz. lean beef, 90 g protein, 30 g EAA, 660 calories), representative of the exaggerated portion size available in many restaurants, can be justified by an increased ability to acutely increase muscle protein synthesis in healthy young and elderly individuals.”
The answer is “No.” Here’s how they measured protein use and what they found.
Using blood samples and thigh muscle biopsies, they found no added muscle gain in the subjects eating the larger meal. Young and old volunteers responded the same. “Despite a three-fold increase in protein and energy content, there was no further increase in protein synthesis after ingestion of 340 g lean beef in either age group,” they reported. “Ingestion of more than 30 g protein in a single meal does not further enhance the stimulation of muscle protein synthesis.” (The analytical method used monitored the blood samples and muscle biopsies, before and after ingestion of the meal, for changes in an amino acid necessary for growth and protein metabolism; details are in the study.)
As indicated earlier, the researchers say it is agreed that “the ingestion of high quality protein [egg, milk, chicken, fish, and beef are examples] is of paramount importance in the maintenance of muscle mass and function.” Moreover, recent research "suggests that moderately increasing dietary protein intake above the recommended dietary allowance of 0.8 g protein/kg/day may enhance muscle protein anabolism." (Emphasis mine) The key finding is that nothing is to be gained by piling on protein in a single meal.
(The researchers acknowledge that some additional protein may be useful in the hour or so after strenuous exercise.)
Paddon-Jones and his colleagues suggest that moderate amounts of protein from various sources be consumed over the course of the day. Unfortunately, few Americans follow this advice.
http://www.cbass.com/Protein_Muscle.htm
The study, led by Douglas Paddon-Jones, PhD, and reported in the September 2009 issue of the Journal of the American Dietetic Association, compared muscle synthesis (formation) and anabolic efficiency in response to meals with moderate and high amounts protein in 17 young (average age 34) and 17 old (average 68 years) volunteers. The subjects were healthy and physically active. Both meals were made up of gently warmed precooked ground beef. One meal contained 30 grams of protein (the rough equivalent of 4 ounces of chicken, fish, dairy, soy, or, in this case, lean beef). The other meal contained three times as much protein, 12 ounces of lean beef and 90 grams of protein.
“We recently demonstrated that a single moderate-size serving of a protein rich food (4 oz. lean beef) acutely increased muscle protein synthesis above fasting values by 50% in both young and elderly individuals,” the researchers wrote in introducing the study. “A 4 oz. serving of 90% lean beef (220 calories) contains approximately 30 g of protein, 10 g of essential amino acids (EAA) and represents 50% of the Recommended Dietary Allowance for a 75-kg [165 lbs] individual.”
The question they set out to answer was whether more protein would stimulate additional muscle building. “[We] sought to determine whether a three-fold larger protein and energy-rich meal (12 oz. lean beef, 90 g protein, 30 g EAA, 660 calories), representative of the exaggerated portion size available in many restaurants, can be justified by an increased ability to acutely increase muscle protein synthesis in healthy young and elderly individuals.”
The answer is “No.” Here’s how they measured protein use and what they found.
Using blood samples and thigh muscle biopsies, they found no added muscle gain in the subjects eating the larger meal. Young and old volunteers responded the same. “Despite a three-fold increase in protein and energy content, there was no further increase in protein synthesis after ingestion of 340 g lean beef in either age group,” they reported. “Ingestion of more than 30 g protein in a single meal does not further enhance the stimulation of muscle protein synthesis.” (The analytical method used monitored the blood samples and muscle biopsies, before and after ingestion of the meal, for changes in an amino acid necessary for growth and protein metabolism; details are in the study.)
As indicated earlier, the researchers say it is agreed that “the ingestion of high quality protein [egg, milk, chicken, fish, and beef are examples] is of paramount importance in the maintenance of muscle mass and function.” Moreover, recent research "suggests that moderately increasing dietary protein intake above the recommended dietary allowance of 0.8 g protein/kg/day may enhance muscle protein anabolism." (Emphasis mine) The key finding is that nothing is to be gained by piling on protein in a single meal.
(The researchers acknowledge that some additional protein may be useful in the hour or so after strenuous exercise.)
Paddon-Jones and his colleagues suggest that moderate amounts of protein from various sources be consumed over the course of the day. Unfortunately, few Americans follow this advice.
http://www.cbass.com/Protein_Muscle.htm
