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. All 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 PERFORMED: Analysis of variance, the paired t test, Pearson's correlation coefficient, and Wilcoxon's ranking test. RESULTS: The mean reported intake between instruments was found to be reliable; however, the comparison with TEE was underreported by 21.4% and was thus nonvalid. Training technique made no difference in validity or reliability. Both training techniques improved the accuracy of food portion estimates; however, improvement was enhanced with food photographs. APPLICATIONS/ CONCLUSION: The findings indicate that training can improve food portion estimates, and dietary instruments may provide reliable but nonvalid results.
RCT Entities:
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. All 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 PERFORMED: Analysis of variance, the paired t test, Pearson's correlation coefficient, and Wilcoxon's ranking test. RESULTS: The mean reported intake between instruments was found to be reliable; however, the comparison with TEE was underreported by 21.4% and was thus nonvalid. Training technique made no difference in validity or reliability. Both training techniques improved the accuracy of food portion estimates; however, improvement was enhanced with food photographs. APPLICATIONS/ CONCLUSION: The findings indicate that training can improve food portion estimates, and dietary instruments may provide reliable but nonvalid results.
Authors: Deborah J Toobert; Lisa A Strycker; Sarah E Hampson; Erika Westling; Steven M Christiansen; Thomas G Hurley; James R Hébert Journal: J Am Diet Assoc Date: 2011-10