These days, there are many different approaches you can take in choosing what you eat. You may be convinced that you can best fuel your body by eating low carb, low fat, meat-free, HFCS-free, additive-free, gluten-free, raw, or prehistoric. Your ethics may lead you to chose to eat vegetarian, to maximize global food supplies, or vegan, so as not to cause suffering to other creatures. Concern for the environment may lead you to choose locally-produced items whenever possible or even to forage from what has been wasted by others. If your interest is in maximizing your culinary experience, you may insist on the freshest ingredients prepared to rigorous standards, or you may be concerned with cooking dishes that are authentic representations of foods eaten in other cultures.
I don't disrespect any of those choices. Science may eventually produce real guidance about what ways of eating are the healthiest, but it can't tell us what's most ethical or most delicious.
Each of these ways of eating has many adherents that live peaceably among us and have no interest in persuading the rest of us to make the same choices they have. But, the times being what they are, each way of eating also has some adherents that believe that their way is the only valid way, that feel (and express) superiority to the rest of us. And it's the shrill voices of the latter group that are most easily heard in the cacaphony.
Here's my point:
Don't be bullied.
If the way you've chosen to eat seems right to you and to whoever you've chosen to advise you, go for it, and ignore the people who want to put you down for it. Those eating in other ways are entitled to choose their own meals.
But they're not entitled to choose yours.
(Note: edited 2/22/11 7:15 to make a small correction.)