OBJECTIVES/GOALS: Self-monitoring (SM) improves adherence to low-fat low-calorie (LFLC) diet for weight management. Ketogenic diet (KD) is a promising alternative to LFLC, however, it is unclear whether SM improves KD adherence. We examined the association between SM and KD adherence during the first 12 weeks of a 6-month technology-assisted lifestyle intervention. METHODS/STUDY POPULATION: We included 30 (50.8 ± 12.4 years, 70% female) overweight/obese (body mass index: 37.1 ± 7.2 kg/m2) participants in the analysis. They received personalized KD goals with very low-carbohydrate (22–62 g/d), moderate protein (52 -87 g/d), and high-fat (115 - 219g/d) and calorie intake goals (1338–2554 kcal/d). Additionally, participants performed daily diet, exercise, and weight SM. Adherence to KD was measured by (1) self-monitored dietary intake, and (2) percent of days in ketosis state (blood ketone≥0.5 mmol/L) captured by a fingerstick blood ketone meter. SM frequency was defined as percent of days participant logged food intake, wore fitness tracker, and weighed body weight. Pearson correlation coefficients were computed to examine the correlation between SM in diet, exercise, and weight with KD adherence. RESULTS/ANTICIPATED RESULTS: Percentage of days participants SM for diet, exercise, and weight was 58.4 ± 32.2%, 66.4 ± 30.9%, and 59.0 ± 32.6%, respectively. Correlational analysis more frequent diet SM was positively correlated with more days in ketosis (r = 0.58, p = 0.003), higher fat intake (r = 0.68, p = 0.0001), and higher calorie intake (r = 0.67, p = 0.002) within the fat and calorie goals set; more frequent weight SM was positively correlated with more days in ketosis (r = 0.48, p = 0.02), higher fat intake (r = 0.45, p = 0.023), and higher calorie intake (r = 0.44, p = 0.027). DISCUSSION/SIGNIFICANCE: We found that diet and weight SM were positively associated with fat and calorie intake, as well as days in ketosis. Given the reported promising effect of KD on weight loss and the challenges of adhering to KD, our findings suggested that promoting SM on diet and weight might be a promising avenue for improving KD adherence leading to successful weight loss.