Thermogenic ingredients and body weight regulation.

The global prevalence of obesity has increased considerably in the last decade. Tools for obesity management, including consumption of caffeine, capsaicin and different teas such as green, white and oolong tea, have been proposed as strategies for weight loss and weight maintenance, as they may increase energy expenditure (4-5%), fat oxidation (10-16%) and have been proposed to counteract the decrease in metabolic rate that is present during weight loss. Daily increases in thermogenesis of approximately 300-400 kJ can eventually lead to substantial weight loss. However, it becomes clearer that certain conditions have to be met before thermogenic ingredients yield an effect, as intra-variability with respect to body weight regulation has been shown between subjects. Furthermore, the sympathetic nervous system is involved in the regulation of lipolysis, and the sympathetic innervation of white adipose tissue may have an important role in the regulation of total body fat in general. Taken together, these functional ingredients have the potential to produce significant effects on metabolic targets such as satiety, thermogenesis and fat oxidation. A significant clinical outcome may sometimes appear straightforward and may also depend very strongly on full compliance of subjects. Nevertheless, thermogenic ingredients may be considered as functional agents that could help in preventing a positive energy balance and obesity.International Journal of Obesity advance online publication, 9 February 2010; doi:10.1038/ijo.2009.299.