Abstract: A composition is provided for suppressing formation of fat in animals comprising a blend of animal feed and polyterpenes of formula (C.sub.10 H.sub.16).sub.n, where n is an inter from 2 to 4. The polyterpenes may be generated in situ by the reaction of citrus essential oils with pharmaceutically acceptable acid or by direct synthesis. A method for suppressing body fat in both animals and humans is also disclosed comprising feeding or ingesting, respectively, polyterpenes prepared either by direct polymerization of neat terpenes or by the aforementioned in situ reaction.