I invited a friend over for dinner and she responded with "I'm a vegan... can I make a dish to share with everyone so you don't have to try to figure it out?" I actually love trying to fit meals I cook into dietary restrictions whether related to health, taste preferences or lifestyle choices in type of meal, so I enjoyed making a vegan meal for everyone - but I thought her response was perfect.

If going out to eat "I'm trying to stick to a vegetarian diet now, can we make sure we choose somewhere with options?"

There will be people who make fun of it, especially depending where you are - but if they do it's really not worth letting yourself care about their opinions if you can control your emotions that well. I would probably go vegetarian for my health and simply the fact I'm not particularly enjoying meat these days if it weren't for my mom's diabetes. Meat is just the easiest protein for her.
The pews never miss a sermon but that doesn't get them one step closer to Heaven.

But at least the pews never attend yoga!