Assessing dietary intake using serial 24-hour recalls in the women's intervention nutrition study (WINS) 3 VS 4 days of intake

The WINS trial, is a clinical trial examining the relationship between dietary fat intake and disease free survival in recently diagnosed postmenopausal breast cancer patients uses serial unannounced telephone recalls to assess the dietary intake. To date we have collected baseline data from over 900 participants with a recruitment goal of 2500. We compared data collected at baseline from the first 614 participants using 3 days averaged (including one weekend and 2 different weekdays) vs a 4 day average (including a Saturday, a Sunday and 2 different weekdays weighted to balance the influence of weekend days). The mean values from the 3 day average compared to a weighted average of 4 days was 1593.12vs 1598.83 Kcal., 50.15 vs 50.49 g fat/day and 27.18 vs 27.31% energy (en) from fat, respectively. The biological and statistical insignificance of these differences (5.71 Kcal, 0.34 fat g, and 0.13% en fat) compared to the potential savings in cost, time and participant burden suggests that collection of intake information on 3 rather than 4 days should be considered for this type of study. WINS is an NCI supported trial, CA 45504.