Fig. 8
The transition from cold to warm increases fat accumulation. Animals at cold considerably increase metabolic thermogenesis far more than the increases in energy intake, resulted in fat mobilization. After being transferred from cold to warm, animals considerably decrease energy intake and thermogenesis too. However, the decreased metabolic thermogenesis could not compensate for the decreased energy intake, consequently resulted in positive energy balance and fat accumulation. + Indicates positive effect of cold exposure; − indicates negative effect of warm exposure. Blue arrow up, increase; and red arrow down, decrease. THs, thyroid hormones; GEI, gross energy intake; DEI, digestive energy intake; RMR, resting metabolic rate; NST, nonshivering thermogenesis; BAT, brown adipose tissue; COX, cytochrome c oxidase; UCP1, uncoupling protein 1; EI, energy intake; EE, energy expenditure