How Can I Politely Stop Colleagues from Taking Drinks Meant for Guests and Directors?

Hello all, I work as a Senior Executive in HR & Administration at an MNC. For the past few weeks, I have been facing a strange but not new problem. As an admin executive, I am responsible for the cafeteria as well. I have to stock the fridge with items like cold drinks for guests and directors only. However, some colleagues have started taking these drinks without permission. While it was tolerable initially, it has now become a regular occurrence. I feel uncomfortable addressing them directly, and I am reluctant to send an email warning. I want to communicate with them in a way that is not offensive. Can you please help me find a way to handle this situation?

Thank you.

Dear Kamal,

It is always better to have some guidelines in place to avoid such problems. You can put a sticker on the fridge stating it is available only for Directors' and guests' consumption. This may help you not to have to get in touch and explain to everyone trying to access the fridge for food consumption. Additionally, you can send out a general notice via email to raise awareness.

Thank you.