As a stand-alone expression, we don't use "Good appetite." It sounds very strange when it's not part of a full sentence. "Enjoy your meal" is the current standard, but Mschil's suggestion of the French "bon appetit" is, traditionally, far more common in English.

Sure, in the USA it is used quite often. appetite - a desire to consume food. Also, a desire for anything specifically stated in the sentence (He has an appetite for football. She has an appetite for romance.) We often say things like "We cooked a lot of food, so I hope you have a good appetite." Sometimes we substitute "healthy" for "good" in statements like this to indicate "big". "Wow, you ate all of that food? You must really have a healthy appetite." And my hope for you is that you continue to have a good appetite for English! (Note: when appetite is not modified by "for something", it always refers to food.)

There is not really an equivalent in English, the closest thing one could say might be the French version "bon apetit". I would just say "enjoy/enjoy your meal".

Hello, My name is maris, which is really nice to get on this site, I took interest in you after reading your profile at (www.italki.com). ([email protected]) I believe age and distance has nothing to do with love, so just drop me an email through my private e-mail address ([email protected]), so that we can communicate better and I send you my images. Thank you. maris.

I have never heard this used in England. 'Enjoy your meal' is used, but that is quite recent, and usually by staff, not between diners.