What if:

-working out decreased the size of your muscles and the more slacking and sitting around you did, the more tight your abdominals would be.
-eating healthy food made you fat and sick, and eating junk food made you slim and healthy
-staying awake caused you to be more rested and sleeping only made you tired
-studying made you dumber and not thinking made you smarter
-you only got nervous and acted like an idiot in front of girls you weren't attracted to
-doing nothing was seen as ambition
-showering just made you stink and brushing your teeth turned your teeth yellow

Sure it would probably mean that the world would be exempt from discipline and the world would be thrown into complete anarchy . It may even cause the Lord of the Flies effect where everyone goes around in their underwear killing eachother. I sure would like to spend a week living in this world. It actually probably would need to be longer since my sitting around would take more than a week to grow my muscles to considerable size.

"See that guy who sits around? He's a real go-getter."
"Why do you have to always eat chips and candy Josser? Why not splurge and get a salad instead?"
"Man, I always act like a doofus around ugly girls!"
"I've got a test tomorrow at 8:00 in the morning... better stay up all night and party."

What a great life it would be.