Buy good cookbooks. Bring your own food to things. That basically sums up our success sticking with it.
Health-wise, my health markers are extremely good. No B12 or iron deficiency. I attribute a ton of this success to consistent physical activity, though, particularly weight lifting.
Regarding physical activity, it comes easy, I am in way better physical health than the bay majority of my peers, if not for my asthma issues. I associate that, again, not with the diet, but with general physical activity.
Basically, the diet doesn't hurt, and statistically isn't likely to help you. The important part is the ecological cost of a diet full of meat, imo, or if someone eats enormous amounts of meat and ends up with a physical malady from it.