Kellogg’s K2O is comes as packets of powder that you mix into a bottle of water. Each one has 30 calories, 5 grams of fiber, and 5 grams of protein. The pink lemonade flavor is decent. Not great–a little too acidic for my taste, but definitely drinkable. I find it’s best if I mix the powder into my water, shake the bottle a bit, then throw it back in the fridge for a while. Letting it dissolve completely ensures that you don’t get any graininess.
It’s meant to help stave off hunger, and I’m finding that it does a pretty dang good job of it.