Chapter Category: Cell Metabolism

From the book Adipose Tissue

Heterogeneity of Adipose Tissue Metabolism

Michael Boschmann

Adipose tissue is a highly specialized organ dealing mainly with processes for storage and release of energy. The underlying metabolic routes of these processes are regulated by a complex network to meet the energy requirements of the body. In times of a positive energy balance, i.e., energy (food) intake exceeding energy requirements, excess energy is stored as fat. In times of a negative energy balance, i.e., energy requirements exceeding energy intake, including the extreme situation of long-term fasting, fat resources are mobilized. Both processes operate in a highly efficient manner to prevent wasting of energy and to ensure survival of the organism. Adipose tissue has a highly adaptive capability for storing large amounts of fat. This can be achieved by increasing fat cell size or fat cell number (see also chapter 10 of this volume). Normally, a human subject has about 10 to 20 kg of body fat. Taking into account a caloric value of about 7,000 kcal per kg fat tissue, an energy reserve of 70,000 to 140,000 kcal (that is 300-600 MJ) is stored in adipose tissue. The caloric value for adipose tissue is lower than that for pure fat, i.e., triglycerides (about 9,000 kcal per kg) because the fatstoring adipocytes are normally not completely catabolized for generation of energy. Body fat mass can increase tremendously (between 40 to 100 kg or more) and this accumulation of excess body fat is called obesity. Obesity is by no means an appearance of the late 20th and the early 21st century. One of the first reports of obesity is the \"Venus of Willendorf\", a small statuette showing clear signs of abdominal obesity.1 Obesity has been found in almost all old medical traditions including Egyptian, Chinese, Indian, MesoAmerican, GrecoRoman and Arabic medicine and there have been already single reports about treating obesity as a disease.1 However, in all these traditions occurrence of obesity was limited to the \"higher classes\".1

Taken from the book

Adipose Tissue

Edited by: Michael Boschmann

More chapters from the book:

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