What is the density of the stored energy in adipose tissue (body fat)?

[hkBattousai]

I think the title is self-descriptive. This question stuck in my mind. I want to learn how much energy is stored in human fat.

Does this amount of energy density change in every human?
If so what is the variance of this distribution?

[mishrashubham]

According to this wikipedia page on Adipose Tissue (http://en.wikipedia.org/wiki/Adipose_tissue), it is 80% fat. Assuming this value is a percentage by mass, and using energy density values from this (http://en.wikipedia.org/wiki/Adipose_tissue) site, energy density of adipose is 0.8*37.7= 30.16 kJ/g

I don't know how this varies among different people, nor could I find any studies regarding this question.