The acute effects of the thermogenic supplement Meltdown on energy expenditure, fat oxidation, and hemodynamic responses in young, healthy males

Despite a restructured food guide pyramid, ambitious Healthy People 2010 guidelines, and an explosion of weight loss products, there is an absence of systemic obesity relief. In fact, obesity is a growing concern and the problem may be accelerating. According to the CDC and results from the Behavioral Risk Factor Surveillance System (BRFSS) survey, obesity rates grew from 19.8% in 2000 to 23.9% in 2005, which is an increase of about 0.82% per year; obesity grew from 23.9% in 2005 to 25.6% in 2007, representing a 0.9% yearly increase [1]. The ramifications of the escalating obesity epidemic include an increased incidence of chronic disease and annual health care expenditure, as well as lost productivity [2].Consumers often ingest diet products to bolster weight loss efforts. Formerly, ephedrine and ephedra were integral components in weight loss supplements. Since the most substantial effect of ephedrine use is enhanced sympathetic nervous system (SNS) activity via increased norepinephrine (NE) release from the nerve terminal, the drug has an impact on all adrenergic receptors (AR). Moreover, the ephedrine compound also has β-AR agonist and α-AR antagonist activity in circulation [3]. Previous investigations indicate that supplemental weight loss products containing a combination of ephedra (ma huang) or ephedrine and caffeine increase resting energy expenditure (REE) and loss of fat mass [4-6]. Therefore, prudent supplementation with ephedra-containing products, in combination with a sensible diet and exercise plan, has the potential to accelerate weight loss.On April 12, 2004, however, ephedra-containing products were condemned by the FDA in response to safety concerns; therefore, manufacturers of nutrition supplements sought to formulate alternative thermogenic weight loss products with comparable effectiveness. As such, supplements containing caffeine and β-agonist compounds similar to ephedra began to appear on the market. Therefore, the Citrus aurantium-derived