Frustrated with friends

I've learned to just smile and say "No. Thank You". No need for an explanation. This is your diet - health and fitness plan. Don't let anyone take it away from you. Have your soldiers stand guard at the gate! I mean that in the most pleasant way possible.... No. Thank you. Thanks for offering - but No. (Are you sure?) Yes. I'm sure. I WILL take a glass of water if you have some. (Let them give you something. Sometimes it shuts them up.)