In spite of negative ideas often associated with the term, fats are a major source of fuel for the body's metabolic processes. Fats are important components of cell membranes.
Fat cells insulate the body from cold and can help protect it from injury.
Fats within the body are often referred to as lipids. In the body, cholesterol is an important substance. It is used to produce hormones, build cell membranes and other needed tissues. Cholesterol circulates to cells throughout your body via your blood. In order for cholesterol to circulate in the bloodstream, cholesterol needs to affix itself to proteins.