Show notes
Our guest today Dr. Stuart Phillips, a professor of kinesiology at McMaster University in Ontario, Canada, who is best known for his research into muscle health and the benefits of dietary protein.Stu is the director of the McMaster Physical Activity Centre of Excellence, a state-of-the-art exercise research and training center. It is devoted to studying and improving the health and well-being of older adults as well as people with chronic diseases and disabilities.In addition to his work in the kinesiology department at McMaster, Stu is adjunct professor in the university’s School of Medicine. He is a fellow of the American College of Sports Medicine and the American College of Nutrition. He received the New Investigator Award from the Canadian Institutes for Health Research, the Ontario Premier’s Research Excellence Award, and the Young Investigator Award from Canadian Society for Exercise Physiology. In today’s interview we discuss: [[00:10:59] A recent study (2017) showed that whole eggs promoted a greater amount of muscle protein synthesis than egg whites, suggesting that there may be benefits to the extra nutrients found in the egg yolk.[[[[00:17:54] Highlights of the recent findings coming out of Kevin Tipton’s group which indicates that the dose-response relationship may depend on the amount of muscle tissue that was recruited during exercise, with the ingestion of 40 g protein further increasing muscle protein.[00:20:43]A 2013 paper from Stu’s group titled, “Dose-dependent responses of myofibrillar protein synthesis with beef ingestion are enhanced with resistance exercise in middle-aged men.”[[[[00:46:56] Stu’s paper, “Muscle Disuse as a Pivotal Problem in Sarcopenia-Related Muscle Loss and Dysfunction.”[00:50:25] The need to add more protein to our diets as we get older, which is something that Dr. Valter Longo discussed on episode 64 of STEM-Talk.[00:56:24 How fasting affects muscle protein turnover, which were topics covered in episode 7 of STEM-Talk, an interview with Mark Mattson, and episode 79, which was an interview with Satchin Panda, author of the “The Circadian Code.”[[01:05:47] Stu’s thoughts on a study that was conducted on behalf of the American College of Sports Medicine that found supplementation with HMB failed to enhance body composition to a greater extent than a placebo.Show notes[[[[[[[[[[[[00:10:59] Ken mentions that many protein-intervention studies use supplementation in the form of whey, which has a clear benefit from a muscle standpoint given its high leucine content and convenience. He goes on to mention, however, that some researchers are starting to look at interventions with whole food protein. A recent study (2017) showed that whole eggs promoted a greater amount of muscle protein synthesis than egg whites, suggesting that there may be benefits to the extra nutrients found in the egg yolk.Understanding this, Ken asks if it is possible that by taking an isolated supplement like whey, we are missing out on a spectrum of other nutrients found in protein rich whole foods?[[[[[00:17:54] The currently accepted amount of protein required to achieve maximal stimulation of myofibrillar protein synthesis (MPS) following resistance exercise is 20–25 g. Ken asks Stu to discuss the recent findings coming out of Kevin Tipton’s group which indicates that the dose-response relationship may depend on the amount of muscle tissue that was recruited during exercise, with the ingestion of 40 g protein further increasing muscle protein.[00:20:43] Dawn explains that aging impairs the sensitivity of skeletal muscle to anabolic stimuli, such as amino acids and resistance exercise. She goes on to bring up a 2013 paper from Stu’s group which reported that, in the context of resistance exercise, “it appears that the MPS “machinery” in older muscles is less responsive to low and modest doses of protein. The key finding from this study being 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 … roughly 6 oz containing 36 g of protein.[[[00:27:52] Multiple studies coming from Van Loon’s lab suggesting that 40 g of protein ingested before sleep can be beneficial for muscle protein synthesis, especially in older individuals.While consuming protein before bed may provide some benefits, it may also be detrimental from a circadian rhythm perspective. Forty g of protein equates to 7 eggs or 5 cups of milk or a substantial steak. Given the importance of sleep to anabolic and other processes, Ken asks Stu for his thoughts on the recommendation of pre-sleep protein feeding.[[00:31:57] Ken asks for Stu’s thoughts on a 2017 paper published by Robert Wolfe in the Journal of the International Society of Sports Medicine, which concluded that the claim that the consumption of dietary BCAAs stimulates muscle protein synthesis or produces an anabolic response in humans is unwarranted.[[[[[00:46:56]Stu talks about one of his papers published in the Journal of Frailty and Aging titled, “Muscle Disuse as a Pivotal Problem in Sarcopenia-Related Muscle Loss and Dysfunction.”[[00:50:25] Stu talks about the need to add more protein to our diets as we get older, which is something that Dr. Valter Longo discussed on episode 64 of STEM-Talk.[[00:56:24] Mark Mattson discussed intermittent fasting in Episode 7 of STEM-Talk. More recently, in episode 79, Satchin Panda of the Salk Institute talked about time-restricting eating. Stu gives his thoughts on how fasting affects muscle protein turnover.[[01:02:13] Dawn brings up that physical inactivity impairs insulin sensitivity and that it is exacerbated with aging. A paper Stu and his colleagues produced examined the impact of two weeks of acute inactivity and recovery on glycemic control, and integrated rates of muscle protein synthesis, in older men and women.[[01:05:47] Stu discusses a study that was conducted on behalf of the American College of Sports Medicine that found supplementation with HMB failed to enhance body composition to a greater extent than placebo.[[Links:Stuart Phillips McMaster faculty pageMcMaster Physical Activity Centre of ExcellenceLearn more about IHMCSTEM-Talk homepage Ken Ford bioDawn Kernagis bio

