Reduction in fat intake is not associated with weight loss in most women after breast cancer diagnosis - Evidence from a randomized controlled trial

BACKGROUND. A reduction in dietary fat intake has been suggested as a metho d to promote weight loss in women at risk for breast cancer recurrence. METHODS. Weight change in response to diet intervention was examined in 101 0 women who bad completed treatment for Stage I, Stage II, or Stage IIIA (A merican Joint Committee on Cancer staging system) primary operable breast c ancer during their first year of participation in a randomized, controlled, diet intervention trial to reduce risk of recurrence. Diet intervention wa s performed by telephone counseling and promoted a low fat diet that also w as high in fiber, vegetables, and fruit. The comparison group was provided with general dietary guidelines to reduce disease risk. Multiple linear reg ression models were used to examine the relations among demographic and per sonal characteristics, changes in diet composition and exercise level, and change in body weight or body mass index. RESULTS. The average weight change in the 1-year period was 0.04 kg for the intervention group and 0.46 kg for the comparison group. For the total gro up, body weight was stable (+/- 5% baseline weight) for 743 women (74%), wh ereas 114 (11%) lost weight, and 153 (15%) gained weight. These distributio ns were similar in the two study groups inclusive of all study participants and for only those women with a baseline body mass index of greater than o r equal to 25 kg/m(2). Initial body mass index and changes in fiber and veg etable intakes, but not change in percent of energy obtained from fat, were associated independently with change in weight or body mass index. CONCLUSIONS. For most women at risk for breast cancer recurrence, diet inte rvention to promote a reduction in fat intake was not associated with signi ficant weight loss. Testing the effect of a substantial change in diet comp osition on risk for breast cancer recurrence is unlikely to be confounded b y weight loss in subjects who were the recipients of intensive intervention efforts. Cancer 2001;91:25-34. (C) 2001 American Cancer Society.