Women participating in a dietary intervention trial maintain dietary changes without much effect on household members

This study examined whether subjects who participated in a 12-mo intervention would maintain their diets 1 yr after the study ended and whether the diets of household members were affected. Premenopausal women, who had at least one first-degree relative with breast cancer (n = 122), were randomized to one of four diets: control, low fat (15% of energy), high fruit and vegetable (FV, nine servings per day), and combination low fat, high FV. Study subjects and one household member were asked to complete the Block '95 food-frequency questionnaire (FFQ) at baseline, 1 yr, and 2 yr. Study subjects also completed 24-h recalls and 4-day food records at baseline and Year 1. Fat and FV intakes by all three assessment methods compared reasonably well except that fat intakes by FFQ were somewhat higher. FV intakes by FFQ in the high-FV and combination arms increased significantly from 4 servings per day to about 10 servings per day at Year 1 and 7 servings per day at Year 2. FV intakes increased much more modestly in the low-fat and control arms. Fat intakes in the low-fat and combination arms were lower at Year 1 than Year 2, but mean Year 2 fat intakes of 26-28% were still significantly lower than those at baseline. In household members, the only significant change was a small decrease in energy from fat at Year 1 in the household members of subjects who were in the combination arm. These results indicate that study subjects were making large dietary changes independently of their household members and that fat and FV intakes in study subjects 1 yr after intervention stopped were still substantially different from intakes at baseline.