The term "lean mass hyper-responder" was coined by software engineer David Feldman on July 3, 2017 while posting in his low-carb diet blog: "Cholesterol Code." The blog post called "Are you a Lean Mass Hyper-responder?" quickly circulated through the low-carb community.
As background, the original term "hyper-responder" was already used by dietary professionals for years prior to Feldman's blog post. And in dietary literature, a "hyper-responder" is someone who adopts a low-carb diet, then experiences dramatic cholesterol elevation. So when Feldman wrote his 2017 blog article, he co-opted "hyper-responder," and crafted his new term "lean mass hyper-responder" to describe what he believes is a metabolically unique sub-set of all hyper-responders. Specifically, some hyper-responders begin a low-carb diet while already in possession of a very lean body mass. And yet in spite of this, they still --quite counter-intuitively-- respond with extreme cholesterol elevation. Additionally, these subjects experience a marked decrease in triglycerides, while exhibiting excellent metabolic health. The entire phenomenon defied a long-standing metabolic theory called "The Lipid Energy Model," presenting a scientific conundrum for Feldman.
Feldman believed that all this was a significant observation worth exploring. And his efforts eventually led to a 2023 research project called "The Lean Mass Hyper-Responder Study" led by Dr. Matthew Budoff and Dr. Nicholas Norwitz at Lundquist, UCLA.
IN A SENTENCE: "Steve has always been a tall, skinny, beanpole of a guy. And then when he went on the carnivore diet, he was still skinny, but his cholesterol went through the roof. His doc said that overall he's pretty healthy, so he might just be a lean mass hyper-responder."