VALIDITY AND RELIABILITY OF REPORTED DIETARY-INTAKE DATA

Objective To compare two training techniques for validity and reliability of dietary instruments and the measurement of total energy expenditure (TEE) to determine whether technique could influence the accuracy of food portion estimates. Design Adult women were randomized into a control group and an experimental group for comparison of training technique. Setting University and research center. Subjects Five hundred women were screened using the Three-Factor Eating Questionnaire to identify restrained eaters or disinhibitors. Other criteria for selection included good health; absence of thyroid, respiratory, or other diseases; normal menstrual cycles; between the ages of 18 and 50 years. Forty-nine were recruited, with an attrition rate of 10% for a total sample of 44 subjects. Intervention The control group (n=26) was trained with food models and the experimental group (n=18) was trained with a combination of food models and life-sized food photographs. Ail subjects completed two 24-hour recalls and 14 consecutive days of food records. TEE was measured by the doubly-labeled water method. Main outcome measures Training would improve the accuracy of food portion estimates. Statistical analyses perfomed Analysis of variance, the paired t test, Pearson's correlation coefficient, and Wilcoxon's ranking test.