Abstract Background: US women have a 1 in 8 lifetime chance of developing breast cancer (BC), with an estimated 10% resulting from a hereditary BC gene mutation. Individuals with mutations in genes such as BRCA1 and BRCA2 have an increased risk of breast and ovarian cancer, as well as other types of cancers. At present, there are more than a dozen other hereditary cancer related genetic mutations that have an associated moderate to high risk of developing cancer. Along with an ability to identify and characterize risk in individuals with a hereditary cancer mutation, there is a need to study modifiable factors such as dietary intake and physical activity in relation to an individual’s risk for cancer. Obesity and poor physical fitness are independently associated with an increased risk of BC and recurrence. There is a paucity of data on the impact of BMI, obesity, and physical activity on primary and recurrent BC in genetic mutation carriers. Women with a moderate penetrance gene mutation are at a high risk for BC and yet are likely to have an impact from modifiable risk factors. The impact of obesity, diet, and physical activity on BC risk and outcomes needs to be further characterized in genetic mutation carriers. Methods: A short REDCap electronic survey was disseminated on social media and through our advocate partner Facing our Risk of Cancer Empowered (FORCE). Eligible participants include males or females, ≥18 years with a hereditary cancer genetic mutation. The survey includes questions regarding personal health, weight, height, metabolic risk factors, reproductive history as well as personal and/or family history of cancer and gene mutation status. In addition, includes a standardized assessment for diet (14-Item Mediterranean Diet Tool) and physical activity (IPAQ and modifiable PAQ). The first 1000 participants are compensated for their time with a $10 e-card. The survey is available in English and Spanish. The Spanish version was developed in collaboration with JUNTOS Kansas City. Objectives: To establish a cohort and describe obesity rates, physical activity, metabolic factors, and nutrition in a cohort of individuals that have an increased risk of cancer due to a hereditary cancer genetic mutation. Results: A total of N = 1,117 surveys have been completed as of June 30, 2020. Of them, 61.2% were removed from final analysis due to incomplete surveys, internet bots, and multiple single-user entries. A total N = 443 surveys have been verified and included in this analysis. Demographics: 98.6% female (n= 437), 94.4% white (n = 418) and median age 46 (range 19 – 77 yrs). Mutations represented in the cohort include: BRCA2 (39.0%), BRCA1 (29.1%), CHEK2 (13.1%), and ATM (5.9%) and < 5%: PALB2, RAD51D, and TP53. Median BMI 24.9 ± 6.06 stdv. BMI 25 to < 30: 26.4% (n = 117). BMI 30 or > 30: 23.47% (n = 104). 61.3% responders are currently trying to lose weight. Attempts at weight loss: No attempts: n = 60 (13.5%), at least 1: n = 55 (12.4%), 2-5: n = 211 (47.6%), 6 or more: n = 117 (26.4%). Limitations to exercise include motivation (26.9%), time (23.5%), not liking exercise (15.6%), and lack of gym memberships (12.4%). 74.9% (n = 332) responded that they are interested in participating in future studies. The Spanish survey was made available 3/3/2020, no responses to date. Conclusion: Individuals harboring a hereditary cancer genetic mutation are interested and willing to participate in research focused on lifestyle modifications and association with cancer risk. Rates of being overweight or obese are high and many have made multiple attempts at weight loss and find common barriers to exercise. Social media is a feasible platform to recruit to a lifestyle research project in a rare population. Additional steps to limit internet trolls, bots, and repetitive responses are necessary but did not impede recruitment. Further effort and collaboration are needed to expand the survey to underrepresented minorities. Citation Format: Lauren E Nye, Kendra Cruz, Sue Friedman, Diane Rose, Christie Befort, Debra K Sullivan, Jill M Hamilton-Reeves, Lisa M Harlan-Williams, Fariba Behbod, Jo Wick, Melinda Irwin, Jennifer Klemp. Energetics and lifestyle in inherited syndromes (ELLIE'S study) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS7-44.