Both animal and human research hints at a possible role for CLA in reducing body fat and increasing lean body mass, but it's not quite ready for prime time. None of the human studies have been long-term. CLA is currently being studied in combination with chromium picolinate. CLA is found naturally in dairy foods and beef and is generally considered safe.
Garcinia Cambogia
The extract from Garcinia cambogia fruit rind contains hydroxycitric acid (HCA), which supposedly curbs food intake, weight gain and storage of excess calories as fat. However, studies have failed to prove G. cambogia is an effective weight-loss aid. The most common side effects are upper respiratory and gastrointestinal symptoms.
Guarana
Caffeine is the effective ingredient in guarana plant seeds. Guarana may have a mild appetite suppressant effect over the short term. It was often used in combination with ephedra until ephedra was banned. The potential side effects are those of caffeine overdose -- insomnia, restlessness, anxiety or panic.
Hydroxymethylbutyrate (HMB)
HMB is a natural byproduct of the breakdown of the amino acid leucine. Bodybuilders use HMB supplements to increase muscle mass. A few small studies have suggested that HMB increases lean mass and decreases body fat when combined with weight training. However, studies with overweight and obese people are needed in order to apply it to weight loss.
