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.


METHODS
Adult women were randomized into a control group and an experimental group for comparison of training technique.


METHODS
University and research center.


METHODS
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.


METHODS
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.


METHODS
Training would improve the accuracy of food portion estimates.


METHODS
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.


CONCLUSIONS
The findings indicate that training can improve food portion estimates, and dietary instruments may provide reliable but nonvalid results.
Howat
P M
PM
School of Human Ecology, Louisiana State University, Baton Rouge.
Mohan
R
R
Champagne
C
C
Monlezun
C
C
Wozniak
P
P
Bray
G A
GA
D000328:Adult; D000704:Analysis of Variance; D015992:Body Mass Index; D015930:Diet Records; D004435:Eating; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D008875:Middle Aged; D010353:Patient Education as Topic; D015203:Reproducibility of Results