Protein’s Journey — Read and Watch

Protein’s Journey: From Meal to Muscle

Follow protein from the plate through digestion and absorption into the renewal of muscle. Explore how meals, physical activity, and aging shape the journey—and what this means for everyday strength.

Read the complete book or watch the narrated series, including a chapter on sarcopenia prevention. Both are free and open to everyone.

Martin J. Coyne, MD, MMI

Read the Book Watch the Series

Read the Book

Explore the science chapter by chapter, with references at the end of each chapter.

Introduction — The Journey Beyond the Plate
Follow dietary protein beyond the plate to the renewal of muscle and the maintenance of everyday function.
Chapter 1 — Muscle Is Always Being Renewed
Explore how muscle continually builds, breaks down, and replaces its proteins.
Chapter 2 — The Meal Is the Starting Point
Learn how amino acid composition and food structure shape the protein entering the body.
Chapter 3 — Digestion: Taking Protein Apart
Follow the physical and enzymatic processes that break food proteins into smaller components.
Chapter 4 — Absorption Has a Rhythm
Compare patterns of amino acid delivery from whey, casein, and different plant protein foods.
Chapter 5 — The Whole Meal Changes the Journey
Explore how food structure and the other components of a meal can change the protein journey.
Chapter 6 — From Intestine to Muscle
Trace amino acids through the intestine, liver, and circulation before they reach muscle.
Chapter 7 — Incorporation: Becoming Muscle Protein
See how amino acids become new muscle proteins and how researchers measure that incorporation.
Chapter 8 — mTOR: A Regulator in the Process
Understand mTOR’s regulatory role and why a signaling measurement does not directly measure protein production.
Chapter 9 — Exercise and the Muscle Response
Explore how exercise, recovery, and inactivity influence muscle’s response to dietary protein.
Chapter 10 — What Is Built, Retained, and Recycled?
Connect protein synthesis, breakdown, and recycling with the amount of muscle protein retained over time.
Chapter 11 — Aging: Where Can the Response Change?
Examine where aging can alter the journey and why absorption, signaling, and incorporation must be considered separately.
Chapter 12 — Choosing Protein Within a Meal
Compare protein foods by realistic portions, essential amino acids, food form, and their place in a complete meal.
Chapter 13 — Amount, Distribution, and Timing
Consider daily intake, meal distribution, and timing in the context of individual needs and activity.
Chapter 14 — From Laboratory Measurements to Human Function
Learn how laboratory measures relate to longer-term changes in strength, mobility, and physical function.
Chapter 15 — Preventing Sarcopenia: Keeping Muscle Active and Nourished
Bring together physical activity, adequate protein and energy, and all nine essential amino acids in a practical prevention framework.
Chapter 16 — Putting the Science on the Plate
Translate the science into meals and daily routines suited to the person eating them.
Conclusion — Following the Complete Journey
Reconnect food, amino acid incorporation, muscle renewal, and the everyday capabilities the journey supports.