Certain types of events are faced in two. Mutual collaboration made of good intentions and concrete actions is the key.
And he is a picky eater, and likes to eat out and
Have his wine. He Don't like vegetables, or health food much, at all.
Your dad has to take the first step. It will be effective for him to make the first effort to detoxify himself from a lifestyle that is harmful to himself. The God Buer can help with this. However, it is necessary for your father to take care of himself at least on an attitudinal level because you cannot tie him to a chair and prevent harmful behaviors.
Talk to him precisely, clarify the situation. I also suggest becoming extremely emotional in these cases and making your dad understand and feel that you love him and that you want him to be well and that it would really hurt you a lot to see him throw away his life. Some are ashamed of being emotional in front of their parents in these cases, but if this is your case, know that it could bring much more benefits to make something understood as the situation really is rather than being emotionally proud and keeping everything inside leaving the understanding of the problem to the case.
how am I? Going to handle this issue?
With heroism
I know it seems like a very trivial answer, but there is nothing more heroic than caring for someone and doing good things to those who deserve them. The stupid modern society considers "heroic" only those who dress up in an idiotic way in comics, but the greatest and most concrete form of Heroism is when we take care of the outside world in a concrete way and according to our real abilities.
This is why I have always considered HP HoodedCobra666 my favorite hero and HPS Lydia and HPS Maxine Dietrich my favorite heroines: because they care about the greater good and do concrete things to improve the universe. In life we are often called to be heroes, even in our own small way, perseverance, courage and strength are the requirements for these heroic gestures: taking care of others, working for Satanism, serving the Gods, the world and people as dear as your dad... this is something truly eroic: you are sacrificing a bit of yourself by putting yourself in a situation that requires perseverance, courage, strenght and concrete skills to help someone who deserves it and do good.
What other form of heroism do you know? And it's normal to feel as discouraged as you are before every great heroic deed, but the fact that you will face the problem anyway means that you are the right person for it. And you will definitely face it, the willpower is noticeable, the initial discouragement is normal, but know that it will evolve into an act of heroism spontaneously, in your concrete actions for your dad.