I used to value it more than I do now. I stayed on a fit and healthy track most of my life...organic, 4+ times/weeek exercising , no junk food, no smoking, no soda, and I still ended up with a chronic immune illness (Rheumatoid Arthritis)at age 36. Actually many people I know who have some of the immune illnesses out there lived healthy lifestyles prior to their disease. These are diseases without causes or cures so a healthy lifestyle doesn't hold as much value to me anymore.
I have friends who drink sodas and smoke and never exercise, AND don't have to go to the doctors like I do all the time.
I think to be most healthy, a balance is best- yes, that means having junk food periodically. Genes play a bigger role than what I thought before. I thought my healthy lifestyle would protect me, but some people can smoke all their lives and live to be 80+ without consequences. I think a healthy lifestyle is false insurance- people think it will ward off diseases but I don't believe that anymore.
Now, I'd put more emphasis on stress relief than staying fit or eating healthy. I believe stress causes more harm than junk food or lack of exercise.