Which is more effective: naturopathy or nutrition healing without homeopathy?

Completely different: You are asking about completely different levels of intervention here, when they're important to work with simultaneously. Nutrition replenishes the body at the physical level, and homeopathy works with your entire healing system -- an energy level. Some naturopathic physicians use homeopathy, but it takes many years' training to become skilled at it. It also depends on why you're seeking help.