Is it normal to think its a good idea to share meals for this reason

If two people share a meal, they will have an easier time figuring out if something is wrong with the food (expired, undercooked, or just not a healthy food in general). For example lets say you eat a sandwhich by yourself and you feel sick afterwards. You dont know if there is something wrong with the food, or if you have a medical condition. But if you share the sandwhich with a friend and you get sick but they are fine, you know nothing was wrong with the food. I remember I used to share my food with my mom and when we had something with dairy, I got sick but she felt fine. Thats how I know I have an intolerance.