If there was something that you could say or do that would cause a patient to place a higher value on their health, it would be common knowledge by now.
It doesn't exist.
Yet, every day there are people who change their diet, begin regular exercise programs, stop smoking, give up alcohol, swear off meat or dairy, start flossing, begin training for a marathon and on and on. Was it because someone nagged them? Unlikely. Lasting health habits are internally directed, and like healing, come from the inside out.
Something inspired them. Something made them angry or disgusted enough to act. They wanted something badly enough to do the work. They hit bottom and resolved to climb out.
The point? They wanted it. You can want it for someone else, but ultimately, they have to want it for themselves. How do you help them want it?