As you age you tend to lose muscle. You can counteract that with exercise and diet. As far as diet, eating meat is important and as you may know I’ve always stressed red meat, and lots of it, as a staple for anyone looking to increase muscle mass and maximize body composition.
In the last four decades I’ve written consistently that the suggested protein intake espoused by agencies and dieticians is way too low, not only for athletes but for those who are getting older – and who isn’t? My take is that you need a minimum of 1 gram of protein per pound of lean body weight if you’re anything more than a complete couch potato, and more if you’re into exercise. And that protein should include significant amounts of red meat.
A new study done at McMaster University backs up some of what I’ve been saying by showing that the current guidelines for meat consumption are not high enough to maintain muscle mass never mind increasing it. This study looks at older individuals,
The research was published in the journal Applied Physiology, Nutrition, and Metabolism. I’ve copied the full paper including references below in case you’re interested.
The study participants were 35 middle-aged men – in their upper 50s. The results of the study were that a 6-ounce serving of 85% lean ground beef resulted in significant improvements in the rate of muscle protein synthesis following exercise. Their conclusion was that the quantity of beef needed for optimal myofibrillar MPS for this age group is double the current recommended serving size of meat.
This study helps to show, and as anyone who’s into exercise already knows, that to build and even maintain muscle mass, you need more protein and more red meat than the conservative establishment recommends.
Dose-dependent responses of myofibrillar protein synthesis with beef ingestion are enhanced with resistance exercise in middle-aged men.
Meghann J. Robinson,a Nicholas A. Burd,a Leigh Breen,a Tracy Rerecich,a Yifan Yang,a Amy J. Hector,a Steven K. Baker,b Stuart M. Phillipsa.
Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, 1280 Main St. West, Hamilton, ON L8S 4K1, Canada.
Department of Neurology, McMaster University, Hamilton, Ontario, Canada.
Corresponding author: Stuart Phillips (e-mail: email@example.com).
Published on the web 9 November 2012.
Applied Physiology, Nutrition, and Metabolism, 10.1139/apnm-2012-0092
Aging impairs the sensitivity of skeletal muscle to anabolic stimuli, such as amino acids and resistance exercise. Beef is a nutrient-rich source of dietary protein capable of stimulating muscle protein synthesis (MPS) rates in older men at rest. To date, the dose–response of myofibrillar protein synthesis to graded ingestion of protein-rich foods, such as beef, has not been determined. We aimed to determine the dose–response of MPS with and without resistance exercise to graded doses of beef ingestion. Thirty-five middle-aged men (59 ± 2 years) ingested 0 g, 57 g (2 oz; 12 g protein), 113 g (4 oz; 24 g protein), or 170 g (6 oz; 36 g protein) of (15% fat) ground beef (n = 7 per group). Subjects performed a bout of unilateral resistance exercise to allow measurement of the fed state and the fed plus resistance exercise state within each dose. A primed constant infusion of L-[1-13C]leucine was initiated to measure leucine oxidation and of L-[ring-13C6]phenylalanine was initiated to measure myofibrillar MPS. Myofibrillar MPS was increased with ingestion of 170 g of beef to a greater extent than all other doses at rest and after resistance exercise. There was more leucine oxidation with ingestion of 113 g of beef than with 0 g and 57 g, and it increased further after ingestion of 170 g of beef (all p < 0.05). Ingestion of 170 g of beef protein is required to stimulate a rise in myofibrillar MPS over and above that seen with lower doses. An isolated bout of resistance exercise was potent in stimulating myofibrillar MPS, and acted additively with feeding.
The authors summarized “we report that in middle-aged men, ingestion of beef promotes a dose–response relation for myofibrillar MPS, with the greatest response occurring with ingestion of 170 g of beef. Leucine oxidation was greatest at the 170 g dose, signifying a shift from synthesis being the sole end point of amino acids toward oxidation. It is not possible to conclude from our data whether 170 g of beef is the maximally effective dose, after which additional protein provision will fail to increase myofibrillar MPS further; however, we speculate that this is likely the case, based on the leucine oxidation responses we observed. Our findings have implications for protein requirements for middle-aged men, in terms of the quantity of protein ingested at a single time, which may have implications for the daily protein requirements to maintain muscle mass with aging.”
Keywords: aging, sarcopenia, muscle, nutrition, protein metabolism, muscle metabolism
The full text of the article is available here for free.