In nutrition-intervention research, it is important to consider the sensitivity of dietary assessment instruments to the changes in nutrient intake or dietary behavior under study.

This presentation describes a measure called « responsiveness, » an index of an instrument's sensitivity to change.

Illustrations of this measure are from two randomized dietary-intervention trials that targeted reductions in fat intake: the Women's Health Trial (WHT), a trial to test whether fat reduction would reduce the risk of breast cancer, and the Eating Patterns Study (EPS), a trial to evaluate a self-help booklet to promote dietary change.

In the WHT, a 4-d diet record (FDDR) was only slightly more responsive to dietary change than was a food-frequency questionnaire (FFQ).