A study on fullness suggests it's all about the viscosity-at least when it comes to oat bran.
Oats are often considered a satiating food ingredient, perhaps due to their beta-glucan content. But studies on oat beta-glucan (in liquids and whole foods) so far yield mixed results. Could it be, then, that the efficacy of oat beta-glucan depends on the type of fortified food product?
A team of Finnish researchers thinks this is a possibility, so they assigned 30 women to breakfast of biscuits and orange juice, with or without added beta-glucan, in a crossover study. Biscuits and orange juice were prepared either as control products, with one product fortified (4 g), or with both products fortified (8 g).
Using visual analogue scales to measure each participant’s perceived hunger and fullness, researchers found the combination of both oat beta-glucan products to be most satiating. Orange juice alone, however, was more effective than biscuits alone.
The results reminded these researchers of a 2011 study in which Dutch researchers found viscous fibers much more satiating than less viscous fibers. So even though solid foods do require more chewing, well-hydrated fibers (with their thick and creamy texture) may cue the body to fullness more effectively. “Even small increases in food viscosity have been found to reduce post-prandial hunger ratings,” the researchers said.
These results, if confirmed with more studies, could very well influence oat bran manufacturers to look increasingly at beverage formats.
Biscuits and orange juice in the study were fortified with Oatwell oat bran from CreaNutrition (Kaiseraugst, Switzerland), a DSM company.