Precoded food records compared with weighed food records for measuring dietary habits in a population of Swedish adults

Abstract

In a cross-over design, 82 women and men recorded their food intake by a precoded 7-day record book (PR) including both standard portions in household measures and photographs, and a weighed 7-day record (WR), respectively. Single 24-h urine samples, for determination of nitrogen excretion, were collected for 39 subjects during the WR period. Comparing the PR to the WR method, the mean intake of some foods, as cheese, was higher, and bread and vegetables lower. For energy and nutrients, the fat energy percent (E%) was higher, and protein E%, dietary fibre, iron, thiamin, folate, carotene and a-tocopherol were all lower. Protein intake registered by the PR method was 20% lower compared to 24-h urine samples, and 11 % lower for the WR method. The results indicate that some of the standard portion sizes, used by the PR method, contributed to the observed differences in food and nutrient intakes. The subjects found it easier and less time-consuming to record their food intake with the PR than with the WR method. The time spent on processing data was reduced by 50% when using the PR method. The results of the study will be used for improvements in the design of the PR for use in large-scale dietary surveys for monitoring dietary habits.