A study of different dietary survey methods among 30 civil servants

A sample of 30 volunteers from a population of 100 Ministry of Agriculture, Fisheries and Food (MAFF) civil servants took part in a series of dietary assessments. Food frequency interview, 24-hour dietary recalls, 7-day weighed food record, duplicate diet analysis and 28-day household food purchase records were all used to estimate intakes of energy and a range of nutrients. When results for energy, fat and iron, using the five different methods, were compared there appeared to be systematic differences between methods. The highest results came from food purchase records for the women and from food frequency interviews for the men. Lowest results came from the duplicate diet analysis for fat and energy but from the 24-hour recall for iron, for men and women alike. The implications of these findings, together with possible explanations for them, are discussed.