Thermo genesis is the generation of heat. It is a normal process in the body that contributes to a certain portion of energy being lost as heat as opposed to being stores in some other form. A decrease in thermogenesis has been thought to contribute to obesity, and so an increase in thermogenesis logically helps fight obesity and promote fat loss. A recent paper critically reviewed possible dietary compounds that have been shown to promote thermogenesis. Specifically, the herbs and spices reviewed were capsaicin, black pepper, mixed spices, green tea, black tea, and caffeine. The review pointed out that under controlled laboratory conditions, there were relatively consistent effects of these compounds of increasing thermogenesis, satiety, and fat oxidation. For example in one study consumption of a breakfast with capsaicin increased thermogenesis by 23%. In another study, caffeinated coffee increased thermogenesis 16% more than decaffeinated coffee. Many of these active ingredients are available in supplement form. It seems reasonable that incorporating these thermogenic herbs and spices into your diet will help in the battle to lose body fat.
Westerterp-Plantenga M, Diepvens K, Joosen AM, Berube-Parent S, Tremblay A. Metabolic effects of spices, teas, and caffeine. Physiol Behav. 2006 Aug 30;89(1):85-91. Epub 2006 Mar 30.