Introducing the Lipid Energy Model (LEM) – a cutting-edge way to rethink cholesterol and lipoproteins, especially on carbohydrate-restricted diets (CRDs)!
💡 When people (especially lean, athletic individuals, aka Lean Mass Hyper-Responders) go low-carb, their lipid profiles often show:
⚡ High LDL-C (the so-called "bad cholesterol")
⚡ High HDL-C (the "good cholesterol")
⚡ Low triglycerides (TGs)
🧬 What’s the molecular mechanism here?
When carbs are restricted, the body shifts to using fat as fuel, triggering a cascade of changes:
1. Fat breakdown: Glycogen stores deplete, and hormone-sensitive lipase (HSL) activates in fat cells, releasing non-esterified fatty acids (NEFAs) into the bloodstream.
2. Liver processing: The liver takes up NEFAs and converts them into triglycerides (TGs), which are packaged into very-low-density lipoproteins (VLDL) and sent out to tissues.
3. Energy delivery: Lipoprotein lipase (LPL), anchored to blood vessel walls, breaks down TGs in VLDL to fuel tissues like muscles. This process transforms VLDL into LDL particles, increasing LDL-C levels.
4. HDL dynamics: During this turnover, VLDL sheds surface components (like cholesterol and phospholipids), which are picked up by HDL particles, boosting HDL-C levels.
🔬 Why does this happen more in lean, active individuals?
High energy demand: Lean people often have higher metabolic rates and energy needs, driving rapid VLDL turnover.
Low adiposity: Less stored fat means the body relies more on circulating lipids for fuel.
🔥 Key takeaway: In this context, the triad of high LDL-C, high HDL-C, and low TGs might reflect a normal, adaptive energy transport system—not necessarily a sign of cardiovascular disease risk.
🩺 The big question:
Does this "hyper-responder" phenotype increase heart disease risk? Or is it just how the body efficiently manages fuel on a CRD? Long-term studies (like coronary imaging) aim to answer this!
💬 What do you think?
Is it time to rethink cholesterol in the context of low-carb and high-fat diets? Let’s dive into science together!
Norwitz, N. G., Soto-Mota, A., Kaplan, B., Ludwig, D. S., Budoff, M., Kontush, A., & Feldman, D. (2022). The Lipid Energy Model: Reimagining Lipoprotein Function in the Context of Carbohydrate-Restricted Diets. Metabolites, 12(5). https://doi.org/10.3390/metabo12050460
#Health #Cholesterol #Keto #LowCarb #LipidEnergyModel LeanMassHyperResponders #ScienceExplained

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