Green Coffee Extract is 800mgA new study suggests taking green coffee bean extract, which is sold as a supplement in the United States, could be a safe and effective way to drop some pounds.Researchers gave up to 1,050 milligrams of green coffee bean extract to 16 overweight adults intheir 20s and monitored their diet, exercise regimen, weight, heart rate and blood pressure for 22 weeks. Without changing their diet or exercise, study subjects lost roughly 10.5 percent - an average of 17 pounds -in overall body weight. No harmful side effects were noted, according to the study presented today at theAmerican Chemical Society national meeting in San Diego.How green coffee bean extract contributes to weight loss is unclear. But Vinson theorizes a chemical in the unroastedbean called chlorogenic acid could be responsible. Other experts suspect the stimulant properties of caffeine could be the culprit.