Food pushers.
They're everywhere during the holiday season.
You know them, they're the folks who insist you take far more than you want. Who ladle gigantic portions of everything on your plate and bully and pressure you into taking more and more and more.
They're also easier than you might think to deal with.
Step 1: Make up a reason why you have to serve yourself. Easiest made up reasons? Either you've recently developed some new weird food intolerance or your doctor's recently reviewed your blood work with you and they're pissed and have very specific instructions for what you're allowed and not allowed.
Step 2: Purposely take significantly less food than you actually want, especially the stuff you think you'll enjoy and want the most, and yes, I realize this is going to upset your hosts.
Step 3: When you've finished your purposely small portions make a minor production with your host of how much you liked such and such and would it be alright if you went back for seconds?
At the end of the meal? You're happy because you've controlled your portions. Host's happy 'cause you loved their food enough to have seconds and has long since forgotten you didn't take all that much to begin with.
Done. Food pusher defused.
[And no, that's not an illustration of my mother-in-law. Mine's lovely (though she is most certainly a food pusher).]