© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For permissions, please email: firstname.lastname@example.org. A paucity of evidence exists regarding the impact of workplace dietary interventions on employees' off-duty dietary intakes. This study assessed the impact of workplace dietary interventions that included nutrition education and environmental dietary modification both alone and in combination on employees' dietary intakes inside (on-duty) and outside (off-duty) of work. A pre-post study on employees' on and off-duty dietary intakes was undertaken. Data were obtained from a complex workplace dietary intervention study (Food Choice at Work Trial). Four manufacturing workplaces were allocated to: Control (n = 111), nutrition education (n = 226), environmental dietary modification (n = 113) and nutrition education and environmental dietary modification combined (n = 400) (2013-14). Seven- to nine-month follow-up data were obtained for 517 employees (61% response) [Control (n = 67), Education (n = 107), Environment (n = 71) and Combined (n = 272)]. Dietary intakes were measured using 24-h dietary recalls. Differences between on and off-duty mean dietary intakes were compared and regression analyses adjusted for potential confounders. Significant reductions in on-duty intakes of total fat (-14.2 g/day, p = 0.000), saturated fat (-7 g/day, p = 0.000), salt (-1.4 g/day, p = 0.000) and total sugars (-8.9 g/day, p = 0.003) were observed in the Combined and in the Environment [total fat (-11.4 g/d, p = 0.017) and saturated fat (-8.8 g/day, p = 0.000)]. In the Combined, significant changes were also observed in off-duty intakes of total fat (-10.0 g/day, p = 0.001), saturated fat (-4.2 g/day, p = 0.001), salt (-0.7 g/day, p = 0.020) and total sugars (-8.1 g/day, p = 0.020). Food service can have a positive impact in our everyday environments, including inside and outside of work. Dietary interventions combining nutrition education and environmental dietary modification can improve employees' on and off-duty dietary intakes.