Although scientists have previously determined the recommended daily amounts of certain nutrients, like calcium and vitamin D, they have yet to determine the appropriate numbers for some, such as fiber.
Casey Weber, doctoral student in human nutrition from Mound City and researcher at Kansas State University, is hoping to better the understanding of a child’s recommended daily allowance of fiber. He recently finished his first of two studies observing children’s dietary fiber.
“Fiber essentially is anything that is not digested or provides a functional benefit, but there’s no easy way to classify what that fiber is,” Weber explained. “While findings exist for adults, there isn’t a lot of information about children and the effects of their fiber intake.”
The way a person’s body ferments fiber after it is taken in, whether it be a child or adult, is extremely important. Higher levels of fermentation could mean short-chain fatty acid production, possibly preventing colon cancer, according to Weber. These products of fermentation also supply a source of fuel for colonocytes and beneficial effects in regards to blood lipids (linked to cardiovascular disease).
Children, starting age 1, have a dietary reference intake (DRI) – which tells parents how much of a particular nutrient their kids should eat. Weber said that the intake amount for fiber is an adequate intake amount (AI) because there is not enough existing information about fiber intake to inform people of a specific recommended daily allowance (RDA).
Weber believes there has not been enough research with appropriate context to support the listed daily fiber adequate intake amount. For example, children may have an daily allowance of 19 grams of fiber, but there is little research to support that amount. Fortunately, there has been improvements in recent technology with new ways of measuring variables that could not be measured in populations of young children in the past.
“I want to determine if more information should be available before we really push for this recommended number. Most people view the recommended intakes as black-and-white. They think it is the concrete amount needed, but that isn’t necessarily the case. I’m interested in how fiber interacts with the large intestines of children. The interactions are a potential measure of other beneficial mechanisms that are taking place.”
In the expert’s first study, which opened the door to further investigations, he was working with the university’s Hoeflin Stone House Early Childhood Education Center. He spent 5 weeks measuring the fiber fermentation levels of 20 healthy kids after they ate a fiber-dense breakfast cereal.
A breath hydrogen test was used to measure the fiber, which indicated the level of fermentation by bacteria in the colon. As the fiber goes through the large intestine, it is fermented into a hydrogen and methane gas. This was measurable through the breath hydrogen test after the kids ate different amounts of the fiber cereal.
“The fermentation is measured because it’s an indicator of suggested healthy metabolism that is happening in the large intestine,” said Weber. “We can measure it without actually looking inside.”
According to Weber, the children were given 25, 50, and 75 percent of the recommended daily amount of fiber in order to be relative to the daily recommendations for kids. This would determine if each child ferments fiber in the same way.
Weber and his team hypothesized that as the fiber increased the production of methane and hydrogen would also increase. The results did not show a significant difference. He explained, “Literature has shown some individuals do not produce any gas with any level of fiber. In-vitro and adult studies indicate that more gas will be produced with increased food supply. There is much to learn about the way fiber is handled in growing children.”
This study also illustrated a few challenges faced when researching the outcomes of food intake on health in children, such as increased selectiveness in food choices, he pointed out. This shows the difficulty in getting children to eat more fiber.
“Adults and children have the same recommendation of fiber per calorie consumed. According to the recommendations, a 5-year-old can need up to 25 grams of fiber. Parents and caregivers are often surprised that the amount we encourage their children to eat is typically only 50 percent of the daily recommendation. Our goal is to provide a science-based fiber recommendation to give children the tools for a healthy start.”
He added that while preparing for and conducting this first study, the biggest surprise to him was the realization of how vague the scientific world’s knowledge is of dietary fiber in kids.
“We’re finding out how many doors are closed that we need to open,” he said.
Weber is conducting a second study that is continuing to look at fiber consumption. This time the study will focus on fiber adaptations between children and adults while using the same fiber cereal and the breath hydrogen test. The study will take place during a 3-week period, while adults and children will be given about 10 grams of fiber per day to incorporate into their regular diet to determine what adaptations occurred and if they increased in fermentative capacity. He hopes to have preliminary results of his second study by fall 2012.
Written by Sarah Glynn