Episode 157: Don Layman on the role of dietary protein in muscle, health, and disease

Today we have one of the world’s foremost authorities on dietary protein and amino acids, Dr. Donald Layman. He is known for his extensive research on muscle development as well as his studies of metabolic regulation for obesity, diabetes, and cardiovascular disease.

Don is a professor emeritus in the Department of Food Science and Human Nutrition at the University of Illinois Urbana-Champaign. He spent 31 years on the faculty before stepping away in 2012. Much of Don’s research over the years investigated the impact of diet and exercise on adult health problems related to obesity, type 2 diabetes and metabolic syndrome.

His lab at Illinois particularly focused on understanding metabolism. He conducted clinical trials for nearly two decades that helped create a new understanding about how to optimize people’s macronutrient balance and metabolism. In addition to his work on metabolism, Don has also conducted extensive research into ways to enhance body composition, increase energy levels and monitor blood sugar.

Today Don works as Director of Research for the American Egg Board and is a nutrition consultant for the National Dairy Council and The National Cattlemen's Beef Association. He also is the Chief Science Officer for Qivana, a natural products marketing company that promotes the weight-loss program that Don developed in his lab at the University of Illinois.

Show notes:

[00:04:02] Marcas asks Don what it was like growing up on a farm in a small town in northern Illinois.

[00:04:29] Marcas asks how small the town was that Don grew up in.

[00:05:16] Don explains how he first became interested in science.

[00:05:39] Don talks about how he realized in college that he wasn’t as good at math as he thought he was. He shares how this shifted his focus away from chemical engineering.

[00:06:27] Marcas asks if Don’s natural intuition and interest for biochemistry stemmed from growing up on a farm.

[00:07:10] Ken mentions that as Don was studying biochemistry, he started looking into protein synthesis with a professor by the name of Arlen Richardson, who was known for his aging research. Ken asks Don to talk about this period and how his interest in protein and muscle evolved.

[00:08:27] Marcas asks Don to explain for listeners the importance of protein as it relates to metabolism and what he means when he talks about protein turnover.

[00:09:36] Marcas mentions that we hear a lot about the need to maintain muscle as we grow older, but that back in the ‘70s and ‘80s when Don was starting his career, there wasn’t much of a focus on muscle, except in terms of athletic performance. Marcas goes on to explain that largely because of Don’s research, we now know that protein is critical in terms of helping people stay healthier as they age. Marcas asks Don to give a sense of just how important protein is for our health span and aging.

[00:12:35] Ken asks if it is true that the inefficiency in muscle protein synthesis begins as early as one’s thirties.

[00:14:11] Ken asks Don to talk about the right amount of protein an individual should consume and mentions that there is much confusion on this issue, largely due to the food pyramid’s recommended daily allowance for protein of 0.8 grams per kilogram of body weight.

[00:15:51] Ken mentions that Don has talked in the past about how 40 percent of women who are 60 and older consume less than the RDA for protein, which is likely the bare minimum. Ken asks if it is reasonable to say that a plant-based diet for older women could be risky.

[00:17:13] Ken asks Don to address the claims that high-protein diets are not good for you, and that too much protein can harm your liver and kidney.

[00:18:47] Marcas shifts gears to talk about the quality of protein consumed. Marcas explains that it is much easier for carnivores to get the right amount of protein than vegans, largely because the amino acid leucine is vital for muscle repair and replacement,...