This thesis argues that late-eighteenth-century British Caribbean doctors created a West Indian diet as the principal preventive measure against the local disease environment. The mortality rate was very high in this region because newcomers had little immunity against yellow fever and malaria. The three populations inhabiting the island, European settlers, enslaved Africans and British soldiers, were all heavily affected, a problematic situation for the empire because it augmented drastically the cost, in human and economic terms, of maintaining this important colony. Contemporary medicine was ineffective against these diseases, and although doctors did not abandon their remedies, they also turned to alternative cures, one of them being a better diet. We follow in particular the life of Thomas Dancer (1750–1811), a Jamaican doctor and botanist who oversaw the public botanical garden in the town of Bath. His work as a botanist was focused on bringing useful plants to the island, including breadfruit as a food for enslaved people. Breadfruit, Dancer and others believed, would have created a profound transformation in enslaved Africans’ nutrition and their health. Its success could have also given Dancer more transplantation opportunities. But the subsequent refusal of the slaves to eat breadfruit and the failure to sustain interest in botany made these goals impossible. Instead, he had greater impact through his book The Medical Assistant (1801), intended to help European islanders with little access to medical expertise. In it, he offered what he thought was the best example of a West Indian diet, which promised to adapt European bodies to the tropical environment by emphasizing the consumption of indigenous vegetables over meat. Situating his dietary recommendations in broader ideas about the body and the tropics current in the late eighteenth century, enables us to better understand the nutritional paradigm of the time in relation to medicine and environment.