ABSTRACT As recreational marijuana laws (RML) expanded marijuana access over the last decade, very little is known about the impact of RML on two costly social behaviors that may arise as a consequence of marijuana consumption: unhealthy eating (i.e., munchies) and sedentary lifestyle (i.e., couch‐lock). Using NielsenIQ Consumer Panel data, we find that the passage of RML led to an increase in the number of grocery store trips that involved “junk food,” as well as the amount of spending. This effect is particularly driven by an increase in ice cream, chips, and candy. Using the Behavioral Risk Factor Surveillance System (BRFSS) and the American Time Use Survey (ATUS), we find that the passage of RML also led to a decrease in exercise, particularly driven by a reduction in cardio, and suggestive evidence of more time spent at home. These results suggest that RMLs have an adverse effect on health through unhealthy eating and reduced physical activity, posing a significant public health challenge to diet‐ and lifestyle‐related chronic conditions.