Why does enteral carbohydrate yield higher energy than parenteral? The following is written in a well-known textbook of surgery: > Each gram of enteric carbohydrate provides 4.0 kilocalories (kcal) of energy. Parenterally administered carbohydrates (eg, intravenous dextrose) yield 3.4 kcal/g What is the explanation for this?

Parenteral carbohydrate is usually **dextrose** which is actually **D-Glucose monohydrate**. Monohydrate implies coupling with a water molecule, such that 1 gram contains a lower relative component of glucose, resulting in a lower kcal yield.

![D-Glucose monohydrate](