The conventional doctor treats the human body like a right idiot. It can do no right. If the body gets a fever, they quench it immediately. If a child gets acne, they pump him full of antibiotics. If an adult has heartburn, they treat with acid blockers. Everything the body does, whether it is greedily absorbing dietary fat and cholesterol from the intestines, or properly raising its blood sugar or blood pressure in response to stresses invisible to doctors, or whatever, must be opposed because conventional doctors know better than the body.
While the human body is not the product of design by an infinite intelligence, as some practitioners of holistic medicine seem to believe, it is the product of >3.5 billion years of selective pressure to survive. It is not perfect, but it is not a right idiot either.
The second approach to medicine is to treat the body as the product of > 3.5 billion years of selective pressure to survive. Understand that what it is doing is probably close to right, may even be close to optimal, and work with the body to improve the situation.