We live and minister overseas. We just spent 3 months stateside on furlough (ie. working vacation), visiting with family (3 weeks), friends (2 months), celebrating holidays (3), birthdays (4), and our anniversary. We visited with friends 2 or 3 times a week, usually over a meal (including desserts). I have to admit that before we went I was concerned about gaining weight. More than once the clothes I bought at the beginning of a furlough didn't fit by the end.
So, here's how it went: I enjoyed every occasion, treated myself to chips and salsa nearly every day we were there (coming from Southern California, chips and salsa are amongst my favorite foods and not readily available where we live!), and most importantly, kept to habits of moderation: No seconds, no snacks, and only the occasional sweet (usually a 1/2 serving when we were visiting others regardless of the day of the week). Those daily chips and salsa always went on my plate as part of a meal--after all these months of NoS, snacking just wouldn't be right--it ruins one's appetite!
And, the good news is that I did not gain a single pound! Not one.

And interestingly enough, now that we are back, several people have asked me if I've lost weight. I haven't (nor inches either, but I'm thrilled to have maintained under what might be considered trying circumstances). My guess is that since I saw my neighbors and friends here day in and day out while losing those 40 pounds on NoS over the course of many months, they never noticed the gradual loss. And now, having been gone for 3 months, they were able to see me with new eyes and see the changes NoS wrought for me over time right under their noses.
My point: NoS habits are POWERFUL. They DO become second nature. They work FOR YOU in all kinds of circumstances. Food is no longer my enemy, but something to be thankfully enjoyed and shared wherever I find myself.