I expect your body will go into emergency preservation mode and begin to create 'glucose like' simple sugars by breaking down Protein(amino acids) stored in you muscles and also powers your brain. Which means you will lose muscle mass while retaining most of the fat stores in your body.
And as a fun side effect of burning protein for energy instead of glucose, you body produces Acetone(paint stripper) from the leftover bits of amino acid and you pass that paint stripper through your urinary tract and pee it out! The Human body doing gross, fun stuff just to mess with you. Huzzar!