Validation of food variety as an indicator of diet quality assessed with a food frequency questionnaire for Western Mali

Objective: To assess the validity of two diet quality indexes - food variety score (FVS) and diet diversity score (DDS) in Western Mali. Design: In two separate studies (A and B), FVS and DDS were derived from a food frequency questionnaire (FFQ) and were compared with the same scores and with measures of nutrient adequacy derived from 2-day weighed records (WR). Setting: Two rural, adjacent villages in Mali, West Africa. Subjects: In study A (1996), 48 women and 27 men (15-59 y) participated. Study B (1999) included 34 women and 36 men (15-45 y). Results: Spearman's correlation coefficients between FVS from the FFQ and WR for men were 0.5 in study A and 0.4 in study B. The corresponding correlations for DDS were 0.2 and 0.4, respectively. Correlations for women were lower, especially in study B. Classification into quartiles was also best for men. Correlations for the two diet variety scores from the FFQ with nutrient adequacy from the WR in study A were about 0.3 for men, but lower for women. In study B, these correlations were around 0.5 for men, whereas for women there was no association. Conclusion: FVS and DDS can be assessed by our FFQ. The two diet variety scores reflect diet quality and are simple tools that can be used for monitoring. The validation study gave better results for men than for women, which has implications for further use of these instruments.