Most of my career I've had mandatory lunch breaks, either required when hourly or implied when salary (based on the norms of when people arrived and left each day). However, the worst was definitely an overnight hourly job I had stocking shelves. We had a mandatory unpaid lunch break in the middle of the night, but even if there was somewhere to go, we weren't allowed to leave the building for security reasons. The doors were locked for most of our shift and would only be opened for an emergency. I think I quit after 3 months.