[Dietary interview. I. Comparison between dietary history versus repeated daily recalls]

In the course of 12 months, 43 men and 53 women aged 30-40 years were subjected to 14 24-hours recalls and one dietary history concerned with their individual dietary habits. The mean values yielded by the first and the second method for energy, 4 nutrient groups and 8 food groups were statistically evaluated and compared with each other, from which the following conclusions can be drawn as to the reliability and the precision of the dietary history: 1. The dietary history permits the quantitative estimate of the energy and nutrient intake in groups of about 50 subjects with an error of less than 10%. Underestimation of the actual food intake is more likely than overestimation. 2. The same holds true for the quantitative estimate of the consumption of foods from great food groups. The method is considerably less precise in case of single food or irregularly consumed foods. The differences between the results from the two methods ranged from 0 to 25%. 3. The precision of the individual results obtained for energy and nutrient intake from the dietary history was +/- 20% with a probability of 80-90%. In 75% of the cases, the differences in the consumption of food groups as determined by the two methods were smaller than 20%. As to single foods, however, individual misestimations ranging from 30 to 50% are to be expected.