All therapeutic decisions must be in the patient's best interests. The safest, gentlest treatment for a given condition must always be the preferred one. In terms of Jewish medical ethics, the rest is merely commentary, to paraphrase Hillel. Physicians are given permission to heal and, moreover, are obliged to heal the suffering. Likewise, the sick must seek healing to preserve their lives.
Prevention is the highest form of healing.
Drugs and surgery have their place in the holy art of healing, but the need to resort to invasive treatment must also be regarded as a failure in prevention. God is saying here that He is preventing disease. Since, in preventing disease, we are emulating God, prevention is the highest form of healing. Physicians do not usually discuss lifestyle changes with their patients. Prevention is on the back burner, and someone has to get burnt to get treated.