 He joined the University of Michigan in 1968.Garn produced a large body of work on many areas of human biology, beginning with human hair and eventually contributing research on determinants of coronary artery disease, somatotype, human races, dental development, skeletal development, nutrition, obesity and bone mineralization, among other subjects.In relation to his study on obesity, he studied over-nutrition and under-nutrition, human fat over the course of the human life cycle and the correlation between growth rate in infants and later fatness.