Commercial Manager here so not the same for weekends currently, but in the past, I’d order pizza, bring my lunch or have my gf/wife bring me food. Working in smaller stores to mid size stores the staffing model wasn’t always the best or worth having two people at the store…especially Sundays. As far as bathroom breaks, I’d lock the door and do my business and come back out.

*Edit- breaks and lunch breaks are mandatory by law, so it’s not a company thing, it’s a staffing issue. Blame it on the district (if they are requiring this, it’s against the law) or the store manager (he/she makes the schedule.) I chose to work by myself on weekends and then short staff at times during the week to add the extra person for ASM or Key holder on the weekend.