Ah pregnancy advice. I think I ignored every single piece that was given to me. I ate shellfish (once I'd gotten over 12 weeks of excessive vomiting), drank coffee, enjoyed a bottle of beer every Friday, ate all cheeses and enjoyed my steak medium. The only thing I didn't eat were peanuts and that's because I'm allergic to them and I didn't drink wine because it made me fall asleep instantly! Don't get me wrong, I didn't eat food from dodgy sources, but considering we live on a small island in the Caribbean and everything is flown in from the US, I figured I'd be ok.
I did come across one barista in a coffeehouse who asked me if I was "allowed" to have caffeine when I ordered a latte (said with disdain). I told him that I was "allowed" to do whatever I wanted as I was an adult.
I think I must have had "fuck off" stamped across my forehead though because nobody so much as said boo to me. No stranger ever tried to touch my bump either which was lucky.
The best advice comes after the baby is born, when EVERYONE is a paediatrican. I live in the tropics and when DS was born in September it was about 35oc - a few weeks after he was born a man approached me, asked me how old my son was and then proceeded to lecture me that he was cold because I didn't have socks on him. I smiled, and asked how long he had been a paediatrician. He said "I have two children so I know". I told him to bugger off.
I also had strange men ask me if I was nursing. Standard response was "none of your fucking business". I find aggression works very well :-) People here are surprised if you bring the baby out of the house before they're 2 months old so there were no doubt a few heart attacks when we brought DS to happy hour when he was a week old. He's now 7 months and doesn't seem any worse off considering his mother is a drunken harpy who refused to put socks on him.
OP, the best way to approach it is to think up some standard witty responses to other peoples' attitudes, that way its a lot more fun standing up for yourself. It also helps maintain your confidence in yourself. Don't let anyone else judge you or make you feel bad about your choices. You want to eat brie, medium steak you go right on ahead as long as you're informed.
Enjoy your pregnancy!