4643 Background: Observational evidence associates energy balance factors, particularly diet, with survival in patients with colorectal cancer (CRC). Consumption of a diet with high glycemic indices has been associated with inferior cancer-specific outcomes, but there is limited prospective evidence that alterations in dietary habits improve cancer outcomes. This was a pilot study to determine the feasibility and acceptability of following a low glycemic load (GL) diet in patients with stage I-III CRC and to assess the nutritional resources necessary to follow the diet. Methods: 18 patients with stage I-III CRC, who completed definitive cancer therapy and consumed an avg daily GL > 150 participated in a 12 week, tailored, in-person dietary intervention with a target GL of ≤102. Compliance was assessed using 24 hour telephone recalls. Acceptability of the diet was assessed using a food acceptability questionnaire, and exploratory correlative laboratories were assessed monthly. Results: 67% of patients were compliant with a low GL diet ≥ 75% of the time, over a 12 week time period. Majority of participants experienced a decrease in BMI and waist circumference, 28% experienced meaningful weight loss defined as ≥ 5%. The nutritionist spent an avg of 6.97 hours (SD 2.18) in-person and 1.58 hours (SD 0.68) by phone with each participant. In the overall group, significant decreases were seen in total cholesterol (7.2% decrease; t = -2.33, p = 0.03), VLDL (26.8% decrease; t = -2.33, p = 0.03) and triglycerides (26.6% decrease; t = -2.29; p = 0.04). All participants were satisfied with the diet; 43% were extremely satisfied. 75% of participants liked the foods they were able to eat “very much” or “extremely”. All participants felt the in-person meetings were helpful. 77% did not feel an online video could replace the in-person meetings. 62% of participants did not feel a virtual meeting (e.g skype, etc.) could replace the in- person meeting while 38% felt it could. Conclusions: Patients with stage I-III CRC are able to follow a low GL diet with an in-person dietary intervention. Significant decreases in laboratory measures confirm the efficacy of the diet in altering metabolic indices. All participants who completed the study were satisfied with the diet, the majority of whom enjoyed the foods and planned to continue to follow the diet after study completion. The majority felt in-person contact with the nutritionist was essential to their success. This study was an essential step in designing a larger scale trial to evaluate the impact of low GL diet on cancer outcomes. Clinical trial information: NCT02129218 .