A lot of physicians think a diet is instructions on a sheet of paper. And patients think that. So the doctor hands them a piece of paper, and then they can't use it to make any changes, so the doctor thinks dietary changes don't work. But your diet is what you eat over time, for your whole life. And the changes come slowly.
Nutrition is all about changing patterns gradually.
You have to understand what foods they eat to begin with and then work with them to make little changes here and there. No, it's the dietitian's. The physician doesn't have time. A doctor's visit isn't very long these days, especially because of managed care. Tell me when you eat.