OBJECTIVES/GOALS: Cognitive decline is associated with obesity, stress, poor sleep, and circadian rhythm misalignment, which are themselves functionally intertwined. Irregular food intake timing exacerbates these all. Prolonged nightly fasting (PNF) aligns food intake with innate circadian rhythms. METHODS/STUDY POPULATION: A nationwide, remotely-delivered, 2-arm randomized controlled trial was conducted to assess feasibility and 8-week outcomes of cognition, stress, sleep, eating behaviors, and general eating habits, after a PNF intervention (14-hr nightly fast, 6 nights/week, no calories after 8pm) compared to a health education control (HEC) condition. Eligible participants were living with obesity, stress (Perceived stress scale-4 (PSS-4) total score ≥5), and memory “not as good as it used to be.” Data were collected via Zoom meetings with participants and trained staff and entered into REDCap. All participants had weekly staff check-in calls to report fasting times (PNF group only) and feedback. RESULTS/ANTICIPATED RESULTS: Eligible participants were enrolled from 37 of 50 US states; N=58, 86% women, 71% white, 93% non-Latinx, mean (SD) 50.1 (5.1) years of age, BMI 35.6 (3.6) kg/m^2. No group differences existed at baseline. Linear mixed-effects models were used to compare group differences across all outcome changes. Compared to the HEC condition, the PNF intervention was associated with improved sleep quality (Pittsburgh Sleep Quality Index; B = -2.52; SE = 0.90; 95% CI-4.30 to -0.74; p=0.006). Stress, everyday cognition, and emotional eating behavior significantly changed over time (p<0.02), but there were no group differences. Analysis of feasibility outcomes are on-going. DISCUSSION/SIGNIFICANCE: Changing food intake timing 6 days per week, to exclude nighttime eating without mandating food quality/quantity change, may benefit many individuals living with obesity, stress and memory decline to improve their sleep. Improved sleep quality may lead to more health benefits over time.