Shia LaBeouf -- From Cabaret to Costco

Shia LaBeouf is getting clean by going back to nature ... as in Nature Valley Bars.

Shia was shopping at the Van Nuys, CA Costco and this was a serious food run. In addition to Nature Valley, it looks like he got "Dirty" Potato Chips and Welch's Fruit Snacks. It looks like he also has a box of Honey Bunches of Oats.

Shia's LaBuff and healthy after all the alcohol-fueled craziness in L.A. and NY.

Something troubling however ... it looks like he only got one flavor of the "Dirty" chips.