A COMPARISON OF DIETARY METHODS IN EPIDEMIOLOGIC STUDIES1

Abstract

Three methods of estimating group and individual dietary consumption have been developed and assessed in a case-control study of diet and breast cancer. The methods comprised a 24-hour recall, a detailed quantitative diet history directed to the most recent two-month period and the two-month period six months before, and a four-day diet diary. There is a high degree of correlation between the estimates of food consumption for the controls using each of the methods. The highest estimate was obtained from the diet history, with a slightly higher estimate in the period six months before than the current period, while the lowest is found In the 24-hour recall. The latter corresponds with the same method in a Nutrition Canada Survey. It is concluded that all methods are applicable to case-control studies, but the diet history Is preferred when current food Intake may be Influenced by a disease.