Oat bran emerged from the Dukan Diet and the need to introduce carbohydrates that have no effect on the pancreas and insulin secretion. More importantly, oat bran has two characteristics that support and explain its slimming effect. The first is its absorption capacity which allows it to gorge itself like a sponge 20 times its volume in water. One tablespoon of 15 grams turns into a large 300-gram bolus in the stomach. Such a bulk fills the stomach and along with the foods from a meal provides a fast and strong feeling of fullness and a lasting satiety. The second is its contact viscosity which allows it to adhere to all the nutrients that surround it when it reaches the small intestine. Since oat bran cannot enter the bloodstream, it traps these nutrients and their calories and carries them into the stools. In this way, oat bran reduces appetite considerably. Furthermore, it causes a steady and painless calorie reduction. Finally, it cooks very well and is used in many different recipes. As such, oat bran and konjac are presently the only two foods that can boast a slimming effect. In 2000, when the Dukan Diet appeared, oat bran was not known; today, it is used in most parts of the world, which means that it has established itself for its nutritional qualities and it now seems hard to imagine a diet that would not recommend a combined use of oat bran.