A simple method to assess fruit and vegetable intake among obese and non-obese individuals

Fruit and vegetable (F&V) consumption is generally associated with the prevention of major chronic diseases. For monitoring purposes, public health researchers require short but reliable and valid questionnaires to assess F&V consumption. The aim of the present study was to validate a brief one-page self-administered fruit and vegetable questionnaire (FV-Q) for obese and non-obese populations.

The validation study was conducted from 2004 to 2006, among a sample of 350 obese and non-obese French-speaking participants. The six-item FV-Q was designed to measure F&V consumption over a seven-day period. It was validated against an interviewer-administered Food Frequency Questionnaire (FFQ) by means of correlation analysis and computing of epidemiologic indices. The analyses were performed separately for obese and non-obese individuals in order to account for potential different reporting patterns and the absence of such validation in obese populations. All the analyses were performed during 2007.

For obese and non-obese participants, the Pearson correlation coefficients between the FV-Q and FFQ were, respectively, r = 0.66 (p<0.0001) and r=0.65 (p<0.0001) for the mean daily intake. Values for sensitivity and specificity were 88.5% and 63.6% for obese individuals and 80.0% and 65.6% for non-obese individuals, respectively. Positive predictive values were moderate in both groups, whereas negative predictive values were very good. Overall, results were very similar for obese and non-obese individuals.

This brief F&V questionnaire can be used to identify people requiring nutritional counseling. Moreover, it can be used for both obese and non-obese populations.