Mortality from colon cancer has rapidly increased in the past decades in Japan, and the increase has generally been ascribed to the Westernized diet, characterized by a high intake of fat and meat. However, fat and meat consumption in Japan stopped increasing in the 1970s. The secular trend of colon cancer incidence and mortality was examined in relation to changing patterns of the consumption of selected foods and nutrients and other related factors in Japan, focusing on the relationship with fat and meat consumption. The incidence and mortality rates of colon cancer both increased almost linearly on a log scale until the early 1990s, the increase then ceasing. The temporal change in fat and meat intake coincided with the incidence of colon cancer approximately 20 years later. Although figures for the consumption of red meat was not available in the early years, red meat accounted for 70-80% of the total meat intake in the mid 1960s and thereafter. Cereal consumption showed a continuous decrease even after the 1970s, that of vegetables showing no marked change. The current observation adds to evidence that red meat intake is an important determinant of colon cancer risk.