A method of orally administering jojoba for fat reduction, blood lipid reduction, and cancer prevention and treatment in humans is disclosed. The method incorporates a sufficient quantity of jojoba, defatted jojoba meal, jojoba extract, defatted jojoba meal extract, naturally derived or synthesized simmondsin, or any naturally derived or synthesized simmondsin derivative or analogue, including aglycon, or any mixture thereof into an individual's diet in the form of a food, dietary supplement, or drug to provide simmondsin component in an amount greater than 0.01% of one's total daily diet by weight, or 0.05 gram/day. The dosage amount and duration of the administration can vary to achieve and maintain one's desired body composition and blood lipid levels. The dosage and duration of administration are increased for cancer prevention and treatment.