The response of lipoproteins to dietary fat and cholesterol is higher in lean than in obese persons – a review

Individuals differ in the response of their blood lipoproteins to cholesterol-lowering diets. One characteristic clearly associated with susceptibility to diet is leanness: many studies show that total, LDL and HDL cholesterol concentrations respond more strongly to dietary fat and cholesterol in lean than in obese subjects. This is unlikely to be due differences in dietary compliance. A metabolic explanation is that obese people have a higher rate of total body cholesterol synthesis. The LDL receptors in their liver cells are partly suppressed by this large stream of endogenous cholesterol coming in from their enterohepatic circulation, and the amount added by dietary cholesterol relative to the endogenous pool would be less than in lean people. Whatever the mechanism, diets low in saturated fat and cholesterol are less effective in the obese; the most effective way for them to normalize their blood lipids is to lose weight, which is, unfortunately, hard to achieve in our society.