Why did schools in Texas stop putting Cokes in vending machines?

I'm in my schools newspaper staff and this is my story. Recently vending machines have stoped selling Cokes. All we have is Coke Zero and some Fuzz, Fusion and Life Water. I asked my principle and he said it was a new state law or something.

If you have any info plz reply
plz dont list obvious facts like sugar intake because in need a more detailed explianation or links because its for a school newspaper

Can't find anything on Texas in particular but Oklahoma has to. It's to fight against childhood/teen obesity. Here's a few article links. You can google more. http://www.danmahony.com/sugarinschool1.htm

http://www.stateline.org/live/ViewPage.action?siteNodeId=136&languageId=1&contentId=15178

http://www.foxnews.com/story/0,2933,194085,00.html

http://www.ncpa.org/iss/reg/2003/pd100903f.html