Some statistical aspects of food intake assessment.

Objective: To present the results of the statistical working group of the EFCOSUM project on estimating the minimum sample size for a pan-European dietary survey.

Background And Methods: Numerous statistical issues are involved when planning a nutritional survey aimed at evaluating various indicators, especially if it will be carried out in different countries. The plenary workshop of the EFCOSUM project has chosen four relevant statistical topics: the sample size estimation for dietary surveys, the number of repeated measurements needed to estimate usual intake for each individual; the statistical presentation of data; and the statistical procedures for estimating the usual intake distribution from a limited number of days of observation.

Under-reporting in dietary surveys--implications for development of food-based dietary guidelines.

Objective: To illustrate issues related to under-reporting in dietary surveys relevant for development of food-based dietary guidelines.

Setting: Food and nutrient intakes in two national dietary surveys are analysed in relation to under-reporting using the concept of cut-off values for the ratio between energy intake and basal metabolic rate as well as biochemical markers of nutritional status.

Results: Subjects with an implausibly low EI/BMR ratio had dietary patterns more close to recommended levels, e.

Analytical approaches to food-based dietary guidelines in the European setting.

Objective: To show the effects of statistical approaches of data analysis to be used in the development of Food-Based Dietary Guidelines (FBDG).

Setting: Databases from dietary surveys in 6 European countries.

Results: Quantile analysis based on iron intake among adult women resulted in differences among European countries regarding (macro) nutrient intake and consumption of food groups.

Nutrient intake of physically fit and unfit men and women.

Objective: Participation in physical activity and following a diet low in fat, saturated fat, and cholesterol and high in fiber are important in the prevention and treatment of cardiovascular disease and other health problems. Despite the importance of both behaviors, little is known about the interactive role of diet and physical activity. The association between physical activity and diet has been studied, but data on the association between cardiorespiratory fitness (CRF), which is an objective measure of habitual physical activity, and diet are lacking in adults.

Comparison of a dietary record using reported portion size versus standard portion size for assessing nutrient intake.

Objective: Because the percentage of missing portion sizes was large in the Aerobics Center Longitudinal Study (ACLS), careful consideration of the accuracy of standard portion sizes was necessary. The purpose of the present study was to investigate the consequences of using standard portion sizes instead of reported portion sizes on subjects' nutrient intake.

Methods: In 2307 men and 411 women, nutrient intake calculated from a 3-day dietary record using reported portion sizes was compared with nutrient intake calculated from the same record in which standard portion sizes were substituted for reported portion sizes.