Mark Hyman spent years as a family doctor, then became the public face of functional medicine in the US: Cleveland Clinic’s Center for Functional Medicine, UltraWellness, a pile of food books, Young Forever. The through-line is that food is a signal, calories included, and that a lot of “hard to diagnose” fatigue, gut mess, and metabolic drift start in the kitchen and the environment.
Pegan (paleo + vegan, in his telling) is the dietary brand. Lots of plants, good protein, fewer ultra-processed carbohydrates. You have heard this from other people. Hyman’s reach is why it still matters. He can put a grocery list in front of an audience that will never listen to a strength coach.
Functional medicine as a guild is the fight. Some of it is “maybe test for things your 12-minute GP visit missed.” Some of it is a long lab panel and a cart of supplements with a thin evidence trail. Hyman is better on food systems and ultra-processed food than he is on every specialty test his ecosystem sells. Eat the vegetables. Be picky about the $4,000 “optimization” panel.
On this site he sits nearer digestion and metabolism than longevity Twitter. If Lyon is muscle and Attia is VO2 max, Hyman is the pantry.