UCP1 and obesity due to melanocortin 4 receptor deficiency: Stimulation of BAT using a β3 adrenoreceptor agonist in obese Sprague–Dawley rats increased resting metabolic rate (by 40%–45%), increased UCP1 content in BAT, reduced abdominal white adipose tissue (WAT), reversed diet-induced obesity and caused browning of WAT despite no change in food intake (9).