Is there a good response for when people lecture you on your food or drink choices, or is it best to sit and take it?

I drink alcohol only a handful of times in a year. I don’t smoke anything. However, on several occasions when I am out at events, drinking Diet Coke (my drink of choice), people have given me little lectures on the evils of diet soda.

One time, I was at a picnic type of party, waiting for my family, and another bunch of people invited me to sit with them. They were eating and drinking, I don’t remember what. I had a bottle of Diet Coke and asked if anybody would like some, and one lady started telling me how she used to drink diet soda until she found out that it “rots your innards.” I remained diplomatic and didn’t say anything but it rubbed me the wrong way.

Another time, I was at a holiday luncheon and I was drinking diet soda, and one of the people at my table started telling me how diet soda is bad for you. I think I said something snarky about how I love when people lecture me on diet soda when they’re smoking and drinking alcohol.

I don’t care if people drink or what they do and maybe they’re feeling like I need a lecture on the evils of my drink of choice. Do you think I should respond in a way that shuts them down, or let it go and sit there and smile sweetly?