Zen does not have strict rules about living, such as how eat or what to wear etc.
But Zen has equired an association with healthy outlooks and the connection between what we think, do and even eat.
It often comes up, "What are Zen Buddhists allowed to do?' Answer; Anything. Well you get it, within laws and conventions. We are not going down the street naked just because we are Zen Buddhists, or refusing to pay for growceries at the supermarket etc. Zen is not another word for 'Enttitled'. Though some seem to think so, nor is it 'code' of living.
The basic stand point of Zen is that all things are Enlightenment, the stones, the grass, the cusshion you sit on, yourself. Therefore Zen is the realization of that. The expansion of your Mind's Eye. So the practices of Zen have evolved to help us do that, to realize our selves in walking, eating, sleeping, even our anger, and of course our meditation.
Generations of people over centuries have contributed to this journey for us, through thier sitting, thier words, thier inspired lives.
Sit, listen to the insense, move with the bell, feel the Taku clap - clap, taste the food as it is there. This is Zen. The forms created centuries ago and the new forms being created are vehicles towards this end.
Does a Zen Buddhist eat Fish, Eggs and Meat? You eat as you can. We evolved Shojin Ryori cooking for the difficult poor situation of the temple. keeping a community fed and healthy, and the temple officers mindful of responsibilty to the community and all beings. It's better to eat meat and be gratefull and Compassionate to the being that died for that dish, than to eat a thousand carrots in Self appreciation "I - the Vegitarian". I'm not attacking Vegitarians, it's a healthy feeling to cut out meat, I'm saying discover the awareness of the responsibility.
You can eat Shojin ryori all the time if you wish, or eat as you please - just be mindfull in your life. If we follow some rule just for the rule or some ideal it becomes poison, don't turn your food into poison.
Food for practice is food for thought, food for the Buddha body.
Mujyo, Jizoan Zendo