I recently had a talk with my sister who brought to my notice that I binge when I eat out but I am mindful when I am eating at home and I realised it was true. So, I got myself a wrist band (those colorful rubbery things) and put it on whenever I go out. This way whenever I bring something to eat near my mouth I see the band and immediately check the portions and the food that I am eating. It is just a reminder that I should watch out for what I am putting in my mouth.
When we going out with friends, while chatting, we hardly realise what and how much we are eating in company. This method helps me stayed focused. Try it out!