In the bad old days, country stars were just as famous for their battles with substance abuse as they were for their music.  HANK WILLIAMS literally drank himself to death... and some say KEITH WHITLEY did the same.

Times change.  TIM MCGRAW now does a three-mile run before each concert.  CARRIE UNDERWOOD and KELLY PICKLER are vegetarians... and BILLY CURRINGTON sucks down coconut water to help maintain his sculpted body.

Billy's strange diet came up when he was asked what we'd find in his tour bus refrigerator.

You'll find lots of coconut water, tons of coconut water. I have a juicer on the bus so it's loaded with beets and carrots and apples and kale and spinach and parsley, and I could go on and on.  It's about 15 or 16 different vegetables that I juice at a time.  It is so healthy for you!

And if you see Billy holding a bottle, it's probably mineral water.  He continues...

Tons and tons of H2O.  Your body is made up of 80% water, period.  It's just the way it is, and you have to drink tons and tons of water to keep your whole entire body flushed.  So when you do that, you clear up your skin, you clear out your insides and toxins... I could go on and on, but water is happening!

(LET ME ASK YOU:  Are you living with a health nut who drives you nuts with their devotion to stuff like coconut water and tofu?  Also, what's the most disgusting health food you've ever seen someone eat or drink?)