Technical Abstract: Objective: Evaluate knowledge of dietary protein and reported increasing protein intake to prevent weight gain among midlife women. Design: A cross-sectional national survey. Participants: 1,824 midlife women (40 – 60 yrs old) from the nine US geographic regions. Women were mostly married (71%), White (76%) and well educated, about half were premenopausal (49%). Variables measured: Frequency of dietary practices to prevent weight gain, Weight Efficacy Lifestyle Questionnaire score, protein knowledge score, current self-reported BMI and weight change over the past two years, current protein intake. Analysis: Separate linear regression models determined associations between weight change, protein knowledge scores, protein intake and increasing protein intake to prevent weight gain. Results: Most women could correctly identify good protein sources, while less than half were able to indicate the daily percent dietary energy recommended from protein. Increasing protein intake to prevent weight gain was reported by 43% of women and was associated with weight loss over a two year period, percent energy from protein, and protein knowledge score. Conclusions and Implications: Increasing protein intake to prevent weight gain was a somewhat common strategy associated with slight weight loss over two years. Education regarding dietary protein requirements may enhance the use of this strategy. Keywords: protein, midlife women, weight control