A person with a type B lipid profile is at much greater risk of heart disease than a person with a type A lipid profile  In an experiment, both type A volunteers and type B volunteers were put on a low-fat diet  The cholesterol levels of the type B volunteers soon dropped substantially, although their lipid profiles were unchanged
The type A volunteers, however, showed no benefit from the diet, and 40 percent of them actually shifted to type B profiles
For at least some of the volunteers in the experiment, the risk of heart disease increased after having been put on the low-fat diet.