77. Protein, Leucine & Longevity: Dr. Layman on Building Muscle, mTOR, and Aging Better

In this episode, Dr. Jones is joined by Dr. Donald Layman, one of the world’s top experts in protein metabolism. They discuss what happens to our muscles as we age, why leucine is a key amino acid for building and repairing muscle, and the amount of protein needed to stay strong and healthy.

Dr. Layman also explains the differences between lifespan, longevity, and health span — and how muscle helps us stay active and independent as we age. You’ll hear why muscle supports recovery from illness or injury, and why it’s essential to protect it long before we reach old age.

You’ll learn why breakfast protein matters most, how to avoid age-related muscle loss, and what the research says about protein and kidney health, cancer risk, and living better for longer. This is your crash course in eating for muscle and aging better.

📌 Dr. Donald Layman

Dr. Donald Layman is a globally recognized leader in the field of protein metabolism and nutritional science. As a Professor Emeritus at the University of Illinois, his groundbreaking research has reshaped our understanding of the role of protein, leucine, and muscle health in aging and metabolism. Over his 40+ year career, he has published extensively on amino acids, mTOR signaling, and dietary strategies that support strength, longevity, and healthier body composition. Today, he continues to educate clinicians and the public on practical, science-based nutrition for lifelong health.

🔗 Learn more about Dr. Donald Layman

Website: www.metabolictransformation.com/meet-dr-donald-k-layman/

Connect with Dr. Greg Jones

Instagram: @doctorjones_doctorjones 

Enovative Wellness Center: https://enovativewellness.com/ 

🔬 Timestamps

• Welcome and introduction (00:00 - 02:32)
• How Dr. Layman became a leader in protein research (02:32 - 04:22)
• The leucine discovery journey (04:22 - 06:53)
• Protein, kidneys, and the BUN myth (06:53 - 09:45)
• Why protein keeps you full (09:45 - 10:41)
• Muscle: the driver of metabolism and longevity (10:41 - 14:01)
• Match your diet to your activity (14:01 - 14:41)
• What leucine actually does in muscle (14:41 - 17:39)
• How mTOR works (and why it’s not the enemy) (17:39 - 22:34)
• Do BCAA supplements actually work? (22:34 - 24:51)
• Best BCAA ratio and why (24:51 - 27:18)
• The leucine threshold & why meal size matters (27:18 - 29:13)
• Plant vs. animal protein: significant differences in leucine (29:13 - 30:40)
• How aging changes protein needs (30:40 - 32:13)
• “Eat less protein for longevity?” Dr. Layman responds (32:13 -36:35)
• How much protein should we really eat daily (36:35 - 39:02)
• Protein for weight loss and metabolism (39:02 - 39:58)
• Older adults need MORE protein (39:58 - 42:38)
• Easy math for calculating your protein goal (42:38 - 44:05)
• When you eat protein matters (front-load the day) (44:05 - 46:56)
• Real breakfast foods that work (46:56 - 47:50)
• What is a catabolic crisis? (47:50 - 50:18)
• Protein powders: what to look for (50:18 - 54:49)
• What about hormones in meat? (54:49 - 56:17)
• Soy vs. beef estrogen comparison (56:17 - 58:21)
• Can you eat too much protein? (58:21 - 01:00:43)
• Athletes vs. everyday adults' protein needs (01:00:43 - 01:02:13)
• Spread protein across meals for max benefit (01:02:13 - 01:02:58)
• The one thing to start doing today (01:02:58 - 01:04:06)
• Earn your carbohydrates (01:04:06 - 01:04:17)
• Where to find more from Dr. Layman (01:04:17 - 01:05:31)
• Closing thoughts (01:05:31 - 01:06:13)