My wife and I have been eating vegan food during weekdays and then non-vegan during the weekends. I've found that for me that has been the best balance. The reason we started was for health reasons: All things equal, the normal amount of vegetables that we ate before was pretty small. We got a couple of easy vegan cookbooks and it has been quite good.

Another advantage for us is that, as a nutritionist friend told me, sometimes people eating Vegan find it difficult to consume their required daily calories. So, it translates in to having to eat "a lot" of vegan food, to get into the 1600 daily calorie intake for me. I've lost several Kilos since we started around 4 months ago.