Fat vs. Glycogen: Understanding Energy Storage Differences

Question
why a gram of fat stores more than six times as much energy as a gram of glycogen...
notice 1g of glucose gives 4Kcal and 1g of fats gives 9Kcal
and thank you very much for your help

Answer
oussama,

Glycogen is a long, highly branched chain of glucose molecules.  Glycogen molecules vary in size from a few hundred glucose molecules to thousands of glucose molecules.  Since glycogen is made of glucose, it has the same calorie content as glucose; 4 calories per gram.  This means that a gram of fat (9 cal/g) has 2.25 times the energy as a gram of glycogen (4 cal/g).

You need to brush up on your physiology, or someone has given you inaccurate information.

Best wishes.

Todd