You absolutely have to want to change in order to change. It's hard to understand why people make many decisions, especially if they don't know themselves. We all do things that we shouldn't, though. It's just a matter of degree and point of view. Making changes in your life for better or worse always requires a decision on your part, conscious or unconscious. In order to change for the better, it requires a conscious decision. But you can never force someone to change. You can only try to make them understand a different point of view and try to lead them to a decision.
I know exactly how you feel. I have an aunt who is basically letting diabetes kill her. She was diagnosed with diabetes nearly 20 years ago, and is now in her early 40s and she is dying. I understand the idea of eating what you want, but this seems like such a preventable death.
As a kid, it was normal for me to go to the hospital with my parents when her blood sugar levels were dangerously high. My parents, and everyone else, would beg her to change her diet, and she would make empty promises. Now she is missing major sections of each of her feet and has dozens of additional health problems that stem from the diabetes. She leads a very miserable life. I wish there was a way to make her see, but everyone lost hope that she would change her ways long ago.
I wish I could give you advice to help you with your parents. I guess you could just ask them how badly they would like to keep their feet?
Nobody can force someone to change their diet and habits. That person has to want to. Apparently, living as long as possible is not high on your parents priority list. And I'm not sure that's a bad thing. I'm not too sure it's on mine either. Sure it would be nice to see my grandchildren grow up, but at what cost? Am I going to have to live to be 100? Stuck in a wheelchair or even worse? Do I want to spend my life watching my weight and eating sald for the once in a blue moon visit I met get from my grandkids when I'm old? I say, let them enjoy life even if it's a bit shorter.
My grandfather passed away in his 70s. My son was about three and my sister had just had a baby and my other sister was pregnant. My cousin actually had a baby the day of his funeral. He missed out on a lot of great grandkids being born and growing up (I have two more myself). My grandmother is still alive. She's in her 90s. But the poor thing had to move in with my parents. She's had falls and broken hips and such. Her hair is almost gone. She can barely walk, etc. So he smoked his whole life and ate whatever and got cancer and died, but up until then he was fine. She took care of herself and is now dying a slow death that's really painful and painful to watch. So who was right? Grandpa or Grandma?