My quick and easy smoothie recipe is:
4t. powdered egg whites
(baking section in the grocery store--just watch that it's all egg
whites and no other stuff like sugar)
1 packet of Stevia (or whatever OP sweetener you like)
1/4c. warm water
(mix those with blender or whatever you have until mixed well)
1/4 c. frozen banana *or* 1/2 c. frozen berries
(mix those in until they're all chopped up nicely--defrosted is okay,
too, just helps to have them frozen for texture and not needing as much
ice)
4-5 ice cubes, crushed
This mixture takes care of a protein and fruit serving (protein is the equivalent of 2 egg whites).