Enzyme plays a key role in calories burned both during obesity and dieting. Ever wonder why obese bodies burn less calories or why dieting often leads to a plateau in weight loss? In both cases the body is trying to defend its weight by regulating energy expenditure. In a new paper, researchers identify the enzyme TANK-binding kinase 1 (TBK1) as a key player in the control of energy expenditure during both obesity and fasting. Source 9c.