Abstract: Cholesterol biosynthesis can be inhibited by suitable inhibitors, such as the statins. However, hypercholesterolaemia, whether familial or diet-induced, and more generally hyperlipidaemia are not adequately addressed by cholesterol biosynthesis inhibitors alone, since the body's cholesterol is acquired by uptake from the diet as well as by endogenous synthesis. Lipid is also taken up from the gut. This problem is addressed by providing one or more molecules having amphipathic regions to inhibit the uptake of cholesterol, and other lipids, from the gut. Obesity may also be treated or prevented in this way, as may atherosclerosis. Examples of suitable molecules having amphipathic regions include natural or variant apoproteins and other proteins and peptides having an amphipathic &agr;-helix composed of at least about 15 amino acids.