A Third Variable in Obesity: The Effects of Brown Adipose Tissue on Thermogenesis

Approaches to weight management which consider only energy intake and/or expenditure do not consistently lead to favorable outcomes. A third variable, thermogenesis, must also be considered in a comprehensive understanding of obesity· Three types of thermogenesis have been outlined-shivering thermogenesis, nonshivering thermogenesis (NST), and diet-induced thermogenesis (DIT). The latter two types of thermogenesis, NST and DIT, may share a common biochemical mechanism which leads to heat production in brown adipose tissue (BAT) which is unchecked by energy needs. Four categories of studies are reviewed which implicate BAT as an important factor in DIT and point to commonalities in NST and DIT. More research is necessary to fully understand the role of BAT in human obesity.