Storage

The skin acts as an organ of energy storage which can be drawn upon under physically challenging situations such as starvation and dehydration. The layer of fat acts as a reserve which can be metabolised to produce energy. This process involves fats being broken down into fatty acids which are in turn broken down into acetyl CoA which can feed directly into the Krebs cycle to produce energy.

Babies have a specialised type of fat known as brown fat which yields energy more easily than other types of fat. They also have a higher proportion of their body weight given over to fat than adults. This is important as babies have a large surface area relative to their weight and are unable to shiver; this makes them vulnerable to heat loss. Breakdown of this brown fat produces the energy required to stay warm. As a child develops muscular control and can use this muscular activity to generate warmth, the importance of the brown fat lessens. Generally adults do not have brown fat.