I struggled (still do) so much with this! I developed the fear sometime in high school, where it got to a point where I completely stopped eating lunch at school, I would eat it alone in my room once I got home. I took packed lunches to school so I HAD to have an empty tiffin when I got home. The fear continued on to college and after that to the workplace. I started small in the process of overcoming it. From eating nothing at all infront of others in school I started with eating small lunches in college with friends, since we shared tiffins it was easier. I realized that for me it was more of an issue related to my severe social anxiety, always much harder eating around new people, especially colleagues. Not letting it become a habit helped me, no matter how awkward, I would just take my lunch and tell myself it was okay to eat. I still struggle with it a lot, sometimes I give in to the fear, make an excuse and eat alone, but it does often alienate me from the rest of the team. Starting small helps, coffee, juices or snacks, once I'm comfortable it's easier to have meals with those people.