Background: Objective methods to improve the measurement of selfreported dietary intake, in particular the timing of eating occasions (EO), are needed. The aim of this study is to describe the timing of EO using self-report (SR) with a smartphone app, actigraphic-based wrist motion (WM), and a continuous glucose monitor (CGM). Methods: Participants (n = 30; 58 ± 11y; 56.7% female; BMI: 33.8 ± 4.1 kg/m2) were enrolled in a behavioral weight loss intervention. Data were collected at baseline. All participants self-reported EO into a smartphone app wore an ActiGraph GT9X on the dominant wrist and CGM (Abbott Libre Pro) for up to 10 days. A validated, actigraphic-based classifier was used to detect EO. A simulation of the glucose-insulin model was used to detect EO timing using CGM data. We described EO timing for the 3 methods (SR, CGM, WM) in terms of first, midpoint, and last EO. We explored the overlap of identifying the timing of EO with applied tolerance periods of ±0, 5, 10, 30, 60, 120 min to all SR mealtimes in comparison to CGM and WM. Data are reported as clock times and median interquartile range. Results: The median first EO for SR, CGM and WM was 08:24 07:00-09:59, 06:55 04:23-10:03, and 10:27 08:24-12:54, respectively. The eating midpoint for SR, CGM and WM was 13:34 11:48-15:39, 14:06 11:54-16:19, 14:28 12:54-16:41, respectively. The median last EO for SR, CGM, WM was 20:20 16:50-21:42, 21:43 20:35-22:16, 20:09 16:38-21:54, respectively. Tolerance periods of ±0, 5,10 min resulted in <50% detection of SR EO by both WM and CGM. The overlap between SR and CGM was between 50%-80% of EO detected with tolerance periods of ±30, 60, 120 min. The over-lap between SR and WM was between 36%-60% EO detected with ±30, 60, 120 min tolerance periods. Conclusions: Determining the timing of EO may be improved with objective measures that include WM and a CGM.