Forming hypotheses is one of the most precious faculties of the human mind and is necessary for the development of science. Sometimes, however, hypotheses grow like weeds and lead to confusion instead of clarification. Then one has to clear the field, so that the operational concepts can grow and function. Concepts should relate as directly as possible to observation and measurements, and be distorted as little as possible by explanatory elements.

MAX KLEIBER, The Fire of Life:
An Introduction to Animal Energetics, 1961

AFTER THE UNITED STATES EXPLORATION EXPEDITION under Captain Charles Wilkes visited the Polynesian atolls of Tokelau in January 1841, the expedition’s scientists reported finding no evidence of cultivation on the atolls, and confessed their surprise that the islanders could thrive on a diet composed primarily of coconuts and fish. Tokelau came under the administration of New Zealand in the mid-1920s, but the atolls remained isolated, visited only by occasional trading ships from Samoa, three hundred miles to the north. As a result, Tokelau lingered on the fringes of Western influence. The staples of the diet remained coconuts, fish, and a starchy melon known as breadfruit (introduced in the late nineteenth century) well into the 1970s. More than 70 percent of the calories in the Tokelau diet came from coconut; more than 50 percent came from fat, and 90 percent of that was saturated.

By the mid-1960s, the population of Tokelau had grown to almost two thousand and the New Zealand government, concerned about the threat of overpopulation, initiated a voluntary migration program during which more than half the Tokelauans moved to the mainland. From 1968 to 1982, a team of New Zealand anthropologists, physicians, and epidemiologists led by Ian Prior took the opportunity to study the health and diet of the emigrants as they resettled, as well as those who remained behind on the islands as their diets were progressively Westernized. This Tokelau Island Migration Study (TIMS) was a remarkably complete survey of the health and diet of all men, women, and children of Tokelauan ancestry. It was also quite likely the most comprehensive migration study ever carried out in the history of nutrition-and-chronic-disease research.