I've used them semi-successfully. I did an experiment with myself as the Guinea Pig right after I got them. I took the pills and then consumed [in one meal] 100g of Carbs from White Rice, White Pasta, and White Potatoes...eating virtually no Fruit or other Sugar Containing foods. I weighed myself the next morning and had neither lost nor gained weight. After the first day, I dropped the Pasta and Rice, but continued to consume copious amounts (50-100g) of carbs from White Potatoes and Bread. At the end of the week, I was horribly constipated and gassy...Weight/Fat-wise, I neither gained nor lost. I stopped using them because the gastric problems were not worth the extra carbs.