In the living will portion of your Advance Directive (Section I) you may direct that your life not be extended by life-sustaining treatment if you 1) are in a terminal condition, 2) are persistently unconscious or 3) have an end-stage condition. Alternatively, you can direct that you are to be given life-sustaining treatment if you are in any of those three conditions.
You also have the ability to direct whether or not you wish to receive artificially administered nutrition (food) and hydration (water) if you are unable to take food and water by mouth in each of the three conditions described. Artificially administered food and water normally involves the surgical insertion of a feeding tube into your stomach.
Oklahoma law does provide that even if life-sustaining treatment or artificially administered nutrition and hydration are withheld or withdrawn, you shall be provided with medication or other medical treatment to alleviate pain, and you will be provided with oral consumption of food and water if you are able to eat or drink.