The energy that is required by the body is primarily stored in the form carbohydrates. The energy from the carbohydrates is easily converted into a usable form which is adenosine triphosphate.
The energy from the carbohydrates can be derived easily but from lipids it is difficult. Lipids contain more energy than carbohydrates because they contain more carbon to hydrogen bonds and when these bonds are broken down they release energy.
This energy is much more than carbohydrates. Hence, the maximum energy in the molecules is in lipids.
