Objective The purpose of this study was to develop, implement, and evaluate the efficacy of an intensive intervention program (IIP) based on motivational interviewing to motivate participants within the dietary study of the Women's Health Initiative (WHI) to meet the study's nutritional goals.

Subjects/Design WHI dietary intervention participants (n=175) from 3 clinical centers were randomly assigned to either intervention or control status. Participants assigned to IIP intervention received 3 individual motivational interviewing contacts from a dietitian, plus the usual WHI Dietary Intervention. Participants randomly assigned to IIP control received the usual WHI dietary modification (DM) Intervention. Percent of energy from fat was estimated at study baseline and at follow-up (1 year later) using the WHI Food Frequency Questionnaire.

Results The change in percent energy from fat between IIP baseline and IIP 1-year follow-up was−1.2% for IIP intervention participants and+1.4% for IIP control participants, giving an overall difference of 2.6% (P<.001). Participants having the highest IIP baseline fat intake (⩾30% energy) showed the largest overall change in percent energy from fat between IIP baseline and IIP follow-up.

Conclusions The results of this study indicate that a protocol based on motivational interviewing and delivered through contacts with trained dietitians is an efficacious way to further lower dietary fat intake among participants exposed to ongoing intervention. These data will be useful in future intervention situations when there is a need to increase motivation to change. J Am Diet Assoc. 2002;102:1631-1637.