good post. The vegan diet will suffice on flaxseeds and walnuts for omega 3s. The main issue with a vegan diet is that they have to regularly include some of the SAME foods daily and that there are no vegan products that naturally contain a quality/quantity amount of vitamin b12. This forces vegans to use a synthetic vitamin in its place. A vegetarian (one who can consume the products that come from the animal, but not the animal itself) has an easy solution to this problem by just consuming dairy products alongside the vegan diet. The omnivore has the most superior diet nutrient-wise "if done properly". The other two are do-able, but involve more routine and discipline and should only be done as a lifestyle choice and not as the road to seek ultimate health/fitness.