Uncoupling protein 1 (UCP1) is the hallmark protein responsible for cold- and 
diet-induced thermogenesis in brown adipose tissue (BAT). UCP1 activity is 
protective against body fat accumulation. UCP1 has re-gained researchers' 
attention in the context of obesity following the realization that BAT is 
present and can be activated in adult humans and of inducible UCP1-expressing 
cells in white fat depots. UCP1-mediated thermogenesis is activated by specific 
food compounds, which function by stimulating sympathetic nervous system 
activity to adipose tissues and/or by acting on the adipose cells directly or 
indirectly, through humoral factors released upon their intake. The impact, 
functional consequences and potential mechanism of action of macronutrients, 
micronutrients and bioactive compounds impinging on UCP1 expression/activity is 
discussed, as well as emerging links between human genetic variation and 
differential responses to potential thermogenic food ingredients. Advances in 
this field can help dietary recommendations and strategies for long-term weight 
loss/maintenance and improved metabolic health.