Even with the present, limited, state of knowledge about nutrition and health it seems to me that we can do significantly better than just avoid all additives or modern foods. I don't have much faith that traditional diets are optimized for long-term health. That said, I agree that this is not a bad heuristic to use on the margin.
Does your being honest have anything more than negligible effects on the amount of honesty in the world? It is not at all obvious to me that the marginal benefit of more vegetarianism is increasing in the number of people who shift towards it.
I probably should have clarified that my actual heuristic is more complex than what I said, for example I do trust science's advice on how to avoid nutrient deficiency and infectious disease.
I can think of reasons to be honest that have nothing to do with the total amount of honesty in the world, but I don't see any reasons to prevent animal cruelty that are unrelated to the amount of animal cruelty in the world. Mostly because I don't see instances as distinguishable and my utility function over the number of "bad things where each instance is indistinguishable" seems to be roughly hyperbolic.
If you think this position is wrong I'd be interested to hear why.
I have noticed that among philosophers, vegetarianism of one form or another is quite common. In fact, I became a vegetarian (technically a pescetarian) myself partly out of respect for an undergraduate philosophy professor. I am interested in finding out if there is a similar disproportion in the Less Wrong community.
I didn't request that this go into Yvain's survey because I want more information than just what animal products you do or don't eat; I'd also like to see nuances of the reasons behind your diet. There are a lot more shades than carnivore/vegetarian/vegan - if you want to be a vegetarian but are allergic to soy and gluten, that's a compelling reason to diversify protein sources, for instance. I'd also like to hear about if you avoid any plant foods (if you think they're farmed in a way that's environmentally destructive or that hurts people or if you have warm fuzzy feelings for plants, maybe). Here are some questions that come to mind: