Ate my lunch...

Okay so I’m a nanny. I recently started meal prepping and asked my bosses if I could keep the lunches in their fridge so I don’t have to bring them back and forth. They said it was no problem. I had one more meal left in there for my lunch today and I go to get it, and someone ate it. I looked through the whole fridge and ended up finding the container washed and in the cabinet. So either they ate it or threw it away, which I find a little rude. I’m not a confrontational person but now I’m left without a lunch and I’m starving. I don’t ever eat any of their food, so that’s why I’m a little shocked. Am I overreacting? Should I say something or let it go? Obviously I’m not bringing my lunches ahead of time anymore