Margarine: A butterlike product made of refined vegetable oils, sometimes blended with animal fats, and emulsified usually with water or milk. It is used as a butter substitute. (From Random House Unabridged Dictionary, 2d ed)Butter: The fatty portion of milk, separated as a soft yellowish solid when milk or cream is churned. It is processed for cooking and table use. (Random House Unabridged Dictionary, 2d ed)Sitosterols: A family of sterols commonly found in plants and plant oils. Alpha-, beta-, and gamma-isomers have been characterized.Hydrogenation: Addition of hydrogen to a compound, especially to an unsaturated fat or fatty acid. (From Stedman, 26th ed)Phytosterols: A class of organic compounds known as STEROLS or STEROIDS derived from plants.Plant Oils: Oils derived from plants or plant products.Dietary Fats: Fats present in food, especially in animal products such as meat, meat products, butter, ghee. They are present in lower amounts in nuts, seeds, and avocados.Soybean Oil: Oil from soybean or soybean plant.EstersFatty Acids, Unsaturated: FATTY ACIDS in which the carbon chain contains one or more double or triple carbon-carbon bonds.Eggs: Animal reproductive bodies, or the contents thereof, used as food. The concept is differentiated from OVUM, the anatomic or physiologic entity.Fats, Unsaturated: Fats containing one or more double bonds, as from oleic acid, an unsaturated fatty acid.Fatty Acids: Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)Cross-Over Studies: Studies comparing two or more treatments or interventions in which the subjects or patients, upon completion of the course of one treatment, are switched to another. In the case of two treatments, A and B, half the subjects are randomly allocated to receive these in the order A, B and half to receive them in the order B, A. A criticism of this design is that effects of the first treatment may carry over into the period when the second is given. (Last, A Dictionary of Epidemiology, 2d ed)Anticholesteremic Agents: Substances used to lower plasma CHOLESTEROL levels.Linolenic Acids: Eighteen-carbon essential fatty acids that contain three double bonds.Diet, Fat-Restricted: A diet that contains limited amounts of fat with less than 30% of calories from all fats and less than 10% from saturated fat. Such a diet is used in control of HYPERLIPIDEMIAS. (From Bondy et al, Metabolic Control and Disease, 8th ed, pp468-70; Dorland, 27th ed)Flame Ionization: Pyrolysis of organic compounds at the temperature of a hydrogen-air flame to produce ionic intermediates which can be collected and the resulting ion current measured by gas chromatography.Food-Processing Industry: The productive enterprises concerned with food processing.Food Technology: The application of knowledge to the food industry.Hypercholesterolemia: A condition with abnormally high levels of CHOLESTEROL in the blood. It is defined as a cholesterol value exceeding the 95th percentile for the population.