Fibre-enriched processed foods promise a healthier version of snacks, but they might not do not keep hunger at bay, a small study suggests.
The researchers found no hunger-limiting effects of chocolate bars containing four different "functional fibres", such as inulin - aka "chicory root extract" - commonly found in fibre-enriched processed foods. Overall, the women in the study were just as hungry come lunch time as they were on a day when they ate a low-fibre bar for breakfast. And their food intake for the rest of the day was similar as well.
The findings, reported 9 July in the Journal of the Academy of Nutrition and Dietetics, are in line with other research on added fibres."In general, added fibres don't work across the board" when it comes to helping you feel fuller longer, said senior researcher Joanne Slavin, a registered dietitian and professor at the University of Minnesota in St. Paul.
That doesn't mean people shouldn't eat fibre-enriched foods, though, Slavin said."It's hard to get people to eat enough fibre. It's one of our shortfall nutrients," Slavin told Reuters Health. "I think putting fibre into foods that people will actually eat is a good thing."
"It would be nice if these foods had an effect on satiety," Slavin added. On the other hand, she noted, they may still help regulate bowel habits or control cholesterol. For the study, Slavin's team recruited 22 young women who were not trying to lose weight. They had each woman eat five different chocolate crisp bars on separate days; four of the bars had one of four added fibres, while the fifth one had no extra fibre.
The women had one bar in the evening and then a bar for breakfast the next morning. They then had lunch at the research lab, where they rated their fullness and hunger on a standard scale. After that, they used diaries to record their food intake for the rest of the day. Overall, Slavin's team found, there were no differences in the women's hunger ratings or food intake with the fibre-rich bars versus the low-fibre one. The fibre did, however, cause more gas and bloating.
The Kellogg Company, which provided the bars used in the study, said the products were developed specifically for the research and are not on the market."This study is part of our ongoing efforts as a fibre leader to support research on potential benefits from different fibres to understand how to provide the best nutrition to our consumers," Kellogg spokesperson Kris Charles said in an e-mail.
It's a common perception that extra fibre fills you up longer. But according to Slavin, subjective feelings of fullness may go beyond the fibre itself. In one study, she and her colleagues found that a breakfast of oatmeal and fruit was more satisfying to people than a liquid breakfast with the same fibre content. Slavin said she thinks it's the total experience of eating fibre-rich foods - the chewing, the sight of a big bowl of oatmeal - that makes people feel more satisfied. "You really know you're eating fibre," she said. With a fibre-added chocolate bar, the experience is different. "With these products, it's like eating a brownie," Slavin said.
(Reuters Health, Amy Norton, July 2012)
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