This chapter focuses on the digestion-growth-protein synthesis. In the natural state, the diet of a crocodilian is carbohydrate free. Traces of free glucose are present in the tissues of the animals eaten, and their livers and muscles also contain glycogen, but by the time digestion has barely begun, the carbohydrates are broken down to lactic acid or ethanol and no detectable amounts of saccharides would be absorbed. In a few experiments described in the chapter, caimans and turtles were given glucose, maltose, lactose, sucrose, and starch by stomach tube. In addition, others were given ground rice, wheat flour, corn meal, and potato flour by mouth. Reducing sugars were determined in the plasma at intervals for one week. Glucose was the only saccharide that elevated the reducing sugar concentration of the plasma, and it was absorbed very rapidly. Apparently none of the other di- or polysaccharides was hydrolyzed.
Corn inclusion at up to 27–36% of diet resulted in equal or improved performance compared to carbohydrate-free diets of equal fat content. Energy digestibility averaged 84.3%. Protein digestibility averaged 86.7%.
I'm not sure if it's unhealthy for them, but crocodilians can't metabolize starch or even most simple sugars.https://www.sciencedirect.com/book/9780080297767/alligator-metabolism-studies-on-chemical-reactions-in-vivoWait, no, I'm wrong. Alligators are the exception, apparently.