You can totally be deprived to Starvin' Marvin levels of deprivation and still be able to exert yourself at your mental and physical pique. Who needs nourishment when you have perseverance. You can eat that, right?
I don't give books star ratings; I give them bite ratings. This is a bite. A book can get up to five of these evil-looking chompers, including half bites.
You can attribute your own wording to the ratings. Five's the best, three's decent, one and under isn't worth the gas to go to the library. I'll leave it to you to fill in the blanks.