Legumes are recognized as low glycaemic products. Therefore, its frequent consumption has been widely recommended by several nutritional guidelines worldwide. In this thesis, we demonstrate that the low glycaemic nature of legumes is mainly due to the structural properties of the cotyledon, which naturally entraps starch and proteins limiting its digestion. In order to understand the mechanisms by which these structural properties of legumes delay starch digestion, red kidney beans were used as model systems to conduct in-vitro digestion and fermentation studies. It was found that the reduced digestibility of starch in beans was dependent on the structural integrity of the cotyledon. Therefore, the processing techniques utilized during food preparation will influence the low glycaemic power of legumes. The results gathered in these thesis led us to conclude that the food matrix plays a crucial role in the way that nutrients are digested and fermented in our bodies. Hence, a healthy diet is maintained by paying attention not only in what we eat (food product) but also on how we eat it (food structure).