The bonus gallery has been updated. Check out the fanart, won't you?
Clearly the Vanaa enjoy eating a wide variety of stuff, but a nice digestible form helps it go down easier – kind of like your daily vitamins. Also, the neurotic Mr. Skwidj there in blue is the Vanaa with the best expressions and body language. Just look at him! I want him to be more confident for his own sake, but then he'd stop getting drawn that way.
I wonder what Vanaa foodfights are like. Anyway, these are clearly not Gel-Oh spheres! They're flavored exotic Nutrient Spheres from a fancy resturaunt specializing in foreign recipies! The sphere is made of fats and oils solidified into a soft and easy to ingest shape that contains all the flavors of the special ingredients. It most certainly does not resemble the Vanaa!
Also, to that random Hunter who saved my bacon on the fight with the Cleric Beast, you have my thanks.