I keep my hands busy by holding on to the cup of tea, the glass of water, diet pop, iced tea, etc. I also hold onto my Hunny's hand.
If there is a snack tray or basket on the table, I sit away from it so it is not in my direct line of sight or within sniffing and whiffing distance if it is especially nose-worthy. Who wants to have a plate of cheesy nacho sniffs enticing them? When it looks like the snacks are going to be passed around the table or people are going to order an appetizer, I leap up and take a trip to the sandbox and avoid it.
When the desire to dine is great, get up, dance, make a music selection, go outside for a whiff of fresh air, ask someone to tell you about their pet, their vacation, etc. to distract you.
re: tighter clothing...
Yep, cinch the belt! It reminds me how uncomfy it will be if I overeat and outgrow my pants...
My personal experience is that once I begin to snack - even if it is celery, a pickle, etc., I want more, and then a teensy bit more...one pickle can easily become four for me so to avoid stimulating my former habits of continuous snackage, I just endeavor to eliminate snacking in between meals.