Abstract Background: Evidence suggests that in-person nutrition education is more effective than written materials in improving diet. The ideal dosage of nutrition education (i.e., number of contacts, intervention duration, type of communication channel) to achieve and maintain dietary change among different populations, including minority populations, is unknown. Few studies have compared the effects of intervention dosage on behavioral outcomes among minority populations. Methods: We compare results from two dietary interventions: ¡Cocinar Para Su Salud! (CPSS) and ¡Cocinar Para Su Salud Junto A Su Familia! (CPSSJASF). CPSS was a randomized controlled trial of a culturally-based dietary intervention among Hispanic breast cancer survivors (n=70; 35/arm) involving 9 group sessions over 12 weeks (4x2-hour nutrition classes, 3x4-hour cooking classes and 2x2-hour food shopping trips; 24-hours total) vs. standard-of-care written dietary recommendations for breast cancer survivors. The CPSS dietary program was developed using a six-step procedural model for designing nutrition education (DESIGN) as the conceptual model. Social Cognitive Theory and the transtheoretical model were used as theoretical frameworks to identify determinants of behavior and objectives for each lesson. All class materials and assessments were developed in Spanish. Focus groups and informal interviews with community residents were conducted to evaluate both class materials and assessment instruments for cultural relevance and format. CPSSJASF was a single-arm pilot study testing a condensed version of CPSS (2x4-hour nutrition + cooking class, 2x4-hour food shopping field trips + cooking class; 16-hours total) among pairs of Hispanic breast cancer survivors and female first-degree relatives (n=6 pairs). Primary outcomes were change in daily fruit/vegetable (F/V) servings and energy from fat at 6 months. We compared results from 34 breast cancer survivors randomized to CPSS intervention (intensive) vs. 6 breast cancer survivors in CPSSJASF (less intensive). Small sample size precluded statistical testing. Results: Baseline characteristics of the two groups were similar. Baseline characteristics for the intensive group (n=34): mean age 55.1 years (SD 9.1); mean BMI 30.4 kg/m2 (SD 5.6); average daily F/V intake 4.8 servings (2.9 targeted F/V excluding legumes/juices/starchy vegetables/fried foods); average daily energy from fat, 28.5%. Baseline characteristics for the less intensive group (n=6): mean age 53.2 years (SD 8.6); mean BMI 28.6 kg/m2 (SD 4.2); average daily F/V intake: 5.1 servings (2.1 targeted F/V); average daily energy from fat, 29.8%. At 6 months, changes in the intensive compared to less intensive groups for daily servings of F/V were +2.0 vs. +1.4; daily servings of targeted F/V +2.6 vs. +1.9 and daily kcal from fat -7.3% vs. -2.2%. Conclusions: Both interventions were effective at improving dietary behavior among Hispanic breast cancer survivors. The more intensive CPSS intervention had a larger impact on behavioral change at 6 months. Further research is needed to determine optimum dosage of dietary interventions that result in sustained behavioral change. Note: This abstract was withdrawn after the Proceedings was printed and was not presented at the conference. Citation Format: Ana Corina Aycinena, Ann O. Gaffney, Pam Koch, Isobel Contento, John Richardson, Katherine Crew, Mary Beth Terry, Dawn L. Hershman, Heather Greenlee, Parisa Tehranifar. Development and comparison of 12-week and 4-week dietary interventions among Hispanic breast cancer survivors. [abstract]. In: Proceedings of the Sixth AACR Conference: The Science of Cancer Health Disparities; Dec 6–9, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2014;23(11 Suppl):Abstract nr B04. doi:10.1158/1538-7755.DISP13-B04