The Zimbabwe Secondary School Science Project (ZIM-SCI) developed student study guides, corresponding teaching guides, and science kits for a low-cost science course which could be taught during the first 2 years of secondary school without the aid of qualified teachers and conventional laboratories. This teaching guide, designed to be read in conjunction with the related student guide, includes instructional strategies, lists of required materials, laboratory procedures, and other information for a four-part unit in which students perform activities and experiments which trace the path of energy found in food. Areas investigated include: (1) food chains and webs (introducing producers, consumers, and decomposers); (2) organisms found in milk; (3) compost and fertilizers; (4) nature and identification of fats and proteins; (5) diets; (6) balanced meals; (7) energy measurement in joules; (8) digestive systems, focusing on the human system; and (9) anatomy and physiology of human teeth. A discussion of how concepts are developed in the unit is provided. Each section in this guide correponds to a given section in the student study guide. (JN)