A patient's LDL cholesterol more than doubled after losing weight on a ketogenic diet, even as his health improved. The lipid-energy model explains this: a lean, insulin-sensitive body burns more fat and uses cholesterol to transport energy to muscles. Cholesterol dynamics are more complex than conventional thinking suggests.
Could getting a six-pack increase your cholesterol? Well, let me tell you a quick story from colleague Dr. Professor Adrian Sotomayor. He was treating a patient with obesity. This man, this patient, began losing weight on a ketogenic diet, a low-carb ketogenic diet. Pound after pound of body fat just fell off. The man went from being obese to overweight and eventually into the normal lean BMI range. And throughout this process, his LDL cholesterol stayed low and stable until he reached a lean, healthy weight. Then suddenly, his LDL made a sharp turn. It more than doubled. It skyrocketed. Why? Because once he was lean and insulin sensitive enough, his body shifted into a higher fat burning mode and started to use a cholesterol transport system to deliver energy to his muscles and to refill his shrinking fat stores. This is the lipid-energy model, a framework that predicts strange counterintuitive outcomes again and again, like this patient's LDL skyrocketing when he lost body fat, or my infamous Oreo versus statin experiment— infamous or famous depending on who you are— and so much more. The takeaway here isn't to label cholesterol, or body fat for that matter, as good or bad. It's to encourage deeper thinking, because too often medicine peers through a keyhole. Let's not do that.
