Objective: Evaluate reported use of the practice of "eating more protein" to prevent weight gain among midlife women. Design: Cross-sectional national survey. Participants: One thousand eight hundred twenty-four midlife women (40-60 y) from the 9 United States geographic regions, primarily married (71%), white (76%), and well educated; half were premenopausal (49%). Outcomes: Frequency of dietary practices to prevent weight gain, Weight Efficacy Lifestyle score, self-reported weight change and body mass index over the past 2 years, and current protein intake. Analysis: Linear regression models determined associations between weight change, protein intake, and reported use of the practice of "eating more protein" to prevent weight gain. Results: Most women correctly identified good protein sources, and the majority could indicate the daily percent dietary energy recommended from protein. "Eating more protein" to prevent weight gain was reported by 43% of women as a practice to prevent weight gain and was associated with weight loss over a 2-year period and with increased percent energy from protein. Conclusions and Implications: Reported use of the practice of "eating more protein" was associated with weight loss over 2 years. Education regarding dietary protein requirements may enhance the use of this practice. (Contains 5 tables.)