Lean Mass Hyper-Responders

Executive summary

* The term “Lean Mass Hyper-Responder” was developed by Dave Feldman in reference to those with the combination of very high LDL and HDL cholesterol alongside low triglycerides. This seemed to be a common pattern among those who were lean, fit, and metabolically healthy when adopting a low carbohydrate diet.

* This week's note looks at two papers, which have examined this phenomenon.

* The first paper (Creighton et al) studied 20 male ultra-athletes – 10 typically consumed a high-carb diet and the other 10 followed a low-carb diet. Total, LDL and HDL cholesterol were higher in the low-carb group. Triglycerides and measurements of insulin sensitivity were better in the low-carb group.

* The second paper (Norwitz/Feldman et al) was based on a web survey of 548 adults and closer examination of a subset of 100 of these, who met Feldman's definition of a lean mass hyper-responder.

* This study found that the lean mass hyper-responders had lower BMI on average. They had similar LDL-cholesterol to other respondents before they changed their diet. Their LDL-cholesterol rose substantially on a low-carb diet. Moderate reintroduction of carbohydrate produced a marked decrease in LDL-cholesterol.

* Both papers hypothesised that there may be a fuel-provision reason why cholesterol increases in low carb athletes. This will be explored further with a review of another Norwitz/Feldman et al paper next week.