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

Author: Rock CL, Thomson C, Caan BJ, Flatt SW, Newman V, Ritenbaugh C, Marshall JR, Hollenbach KA, Stefanick ML, Pierce JP

Author affiliation: Department of Family and Preventive Medicine and Cancer Prevention and Control Program, University of California at San Diego, La Jolla, California 92093-0901, USA. clrock@ucsd.edu

Publication date & source: 2001.01.01, Cancer., 91(1):25-34.

Publication type: Clinical Trial; Randomized Controlled Trial; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, P.H.S.

BACKGROUND: A reduction in dietary fat intake has been suggested as a method to promote weight loss in women at risk for breast cancer recurrence. METHODS: Weight change in response to diet intervention was examined in 1010 women who had completed treatment for Stage I, Stage II, or Stage IIIA (American Joint Committee on Cancer staging system) primary operable breast cancer during their first year of participation in a randomized, controlled, diet intervention trial to reduce risk of recurrence. Diet intervention was performed by telephone counseling and promoted a low fat diet that also was high in fiber, vegetables, and fruit. The comparison group was provided with general dietary guidelines to reduce disease risk. Multiple linear regression models were used to examine the relations among demographic and personal 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 group, body weight was stable (+/- 5% baseline weight) for 743 women (74%), whereas 114 (11%) lost weight, and 153 (15%) gained weight. These distributions were similar in the two study groups inclusive of all study participants and for only those women with a baseline body mass index of > or = 25 kg/m2. Initial body mass index and changes in fiber and vegetable 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 intervention to promote a reduction in fat intake was not associated with significant weight loss. Testing the effect of a substantial change in diet composition on risk for breast cancer recurrence is unlikely to be confounded by weight loss in subjects who were the recipients of intensive intervention efforts. Copyright 2001 American Cancer Society.