You can disguise your choices about food, to make it more about health reasons, weight loss etc. I personally do the Paleo diet, and when people ask I make it about general health. Or you can just tell them that your allergic to wheat, etc. This works for some alcoholics. To tell people that you don't eat starch because it will put you pain, they can't understand, but if you put it a context they can understand, they might not argue.
One of the reasons I like the Paleo diet is the reasoning behind it. Having a degree in Biology, it helps me to have a biologic foundation to understanding why a diet works. It doesn't hurt that I am athletic and make it about actual nutrition. And I don't tell anyone outside family about the AS. Some people I just tell them I have arthritis issues, but never details. Good luck.
