Dr. Gabrielle Lyon argues we've been focusing on the wrong idea for 50 years…the problem isn't that we're over-fat, it's that we're under-muscled.
Skeletal muscle makes up 40% or more of your body and is an underrecognized endocrine organ that secretes myokines (signaling molecules) when contracted, impacting the brain, liver, pancreas, and truly every body system. Yet skeletal muscle wasn't even considered an organ system until about 25 years ago!
The diseases we think of as obesity-related—type 2 diabetes, Alzheimer's, cardiovascular disease—are actually diseases of skeletal muscle first, decades before symptoms appear. When Dr. Lyon asked a PCOS expert what body fat percentage contributes to infertility, the answer shocked her: "It has nothing to do with body fat percentage—it has everything to do with the fat infiltrated into the muscle, the intermuscular adipose tissue (IMAT)."
The new US Dietary Guidelines (which Dr. Lyon witnessed being announced on stage) recommend 1.2 to 1.6 grams of protein per kg for the first time in history, a tremendous change based on randomized controlled trials instead of epidemiology. Her mentor, Dr. Donald Layman, wrote the protein portion of the guidelines, and 90% of those guidelines are reflected in her new book, Forever Strong Playbook, released on January 27th of this year.