Americans have always battled with their weight, with 2/3 of the country now weighing in at weights that are overweight or obese. Stanley Schachter developed the internal-external theory that proposes that heavier people are more likely to be encouraged to eat by external cues rather than internal cues. This means that overweight or obese individuals are likely to eat more and more often based on the time of day, the appearance of food, and social circumstances instead of a growling stomach or feeling full.
Have you ever thought you were full, but then saw a huge juicy burger or your favorite ice cream, and all of the sudden you feel ravenous? I know there are plenty of times when I have felt hungry just because something smelled or looked good or just because my friends were eating. Even boredom can initiate hunger. Maybe the internal-external theory applies to more people than just obese individuals. Perhaps it's how often these external cues stimulate a person to eat. Maybe it's the ratio of hunger driven by internal cues to hunger driven by external cues that a person experiences on a day-to-day basis.
External cues are only a part of the factors that cause people to overeat. Since Americans are always interested in breaking the cycle of overeating and losing weight, the question is, what can be done to prevent these external cues from causing people to think they are hungry? After all, eating right and exercising can only help you so much when all of your friends are eating greasy pizza right in front of you.
I think this is a very important topic and one that I can relate to. After coming to college, I feel like I have been overeating a lot more than I did at home. External cues make a huge difference for me. At home I never had food in my room, because it was kept in the kitchen. Here, though, I live in a dorm and so my room is the kitchen and hence my food is easily accessible for me. Another factor is friends, as you mentioned, when I'm invited to go eat at this place or get coffee, it's hard to say no. I don't want to be antisocial, so I go with and even if I wasn't planning on buying anything, once at the restaurant or Starbucks, its even more difficult to say no.
It would be hard for society to control these external cues as a whole and so I think its more of a personal ordeal: Remove the food from your room, do other activities with your friends, etc.