If you google carb blocker you'll find lots of examples, Hana
Here is one claim : 'medically proven to reduce the absorption of carbs by 66-75%, resulting in the intake of far less calories. It is a non-stimulant and an entirely natural ingredient that works to neutralise starch that is contained in foods like potatoes, breads, pasta, rice, corn and crackers. In simple terms, it uses a protein extracted from white kidney beans, proven to reduce the absorption of starch by 75% '
Theere is a paper about this bean extract from the British Journal of Nutrition
http://www.ncbi.nlm.nih.gov/pubmed/18331662
The nutraceutical role of the Phaseolus vulgaris a-amylase inhibitor (what a title)
( you can get the full version but very technical ,so right up your street Hana)