- Consuming a diet containing adequate fiber is associated with maintaining a healthy weight.
- An animal study recently sought to determine which form of fiber might be most effective.
- Beta-glucan, a fiber found in grains and oats, came out on top.
A new study using a mouse model of obesity concludes that a type of fiber called beta-glucan induces more weight loss than other forms of fiber.
If the results are confirmed by human studies, the authors suggest that beta-glucan could be a “promising dietary strategy for metabolic diseases.”
The search appears in Journal of Nutrition.
To understand the study results and provide practical advice, Today’s Medical News We contacted several experts for their opinions, but none of them participated in the study.
Not long ago, people thought fiber was just “dietary fiber”—it kept your bowels regular, but that was it. Today, we know fiber is essential for gut health and overall health.
Our digestive system cannot break down fiber, so it passes through most of the digestive tract.
Once it reaches the large intestine, where most of our gut microbiome resides, bacteria ferment it. During this process, the microbes release a series of health-promoting compounds, such as short-chain fatty acids (SCFAs).
MNT I reached out to Dr. Mir Ali, a board-certified bariatric surgeon and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, California. He emphasized the important role of dietary fiber in health:
“A high-fiber diet has many benefits: lowering cholesterol and blood sugar; maintaining regular bowel movements and good gut health; reducing the incidence of diverticulitis and other intestinal conditions, to name a few.”
Janese Laster, MD, board certified in internal medicine, gastroenterology, obesity medicine and nutrition, explained:
“We know that by increasing the amount of fiber in the diet, we can also alter the human microbiome, promoting satiety, which reduces overeating and weight gain, and creating changes in metabolic health.”
She also said MNT that a high-fiber diet can help regulate blood sugar levels, reducing insulin resistance. According to Laster, short-chain fatty acids
According to Laster, when his patients increase their fiber intake, “many see improvements in their energy levels, sleep and reduced brain fog.”
But while the benefits of a high-fiber diet are clear, questions remain. Fiber isn’t a monolith: There are many forms of it, but scientists aren’t sure which ones impact which aspects of metabolism. The latest study addresses that question.
Broadly speaking, dietary fiber can be divided into two forms, both of which are important for health:
- Soluble fibers: Dissolves easily in water and produces a gelatinous substance. This form of fiber can help lower cholesterol and blood glucose levels.
- Insoluble fibers: Instead of dissolving in water, it absorbs water. This form of fiber is particularly important for healthy intestinal transit.
For their study, the researchers used a mouse model of obesity. Each animal received one of the following five types of fiber daily for 18 weeks:
- Pectin: A soluble fibers present in fruits.
- Beta-glucan: A soluble fibers commonly found in nature, including grains, yeast, mushrooms, and algae.
- Wheat dextrin: A soluble fiber sold over the counter as a fiber supplement.
- Resistant starch: A type of starch that works similarly to fiber by avoiding digestion and being fermented in the colon.
- Cellulose: A insoluble fiber present in plant cells.
The scientists measured the animals’ body weight, body fat percentage, energy consumption and glucose tolerance. They also analyzed their gut microbiome and the short-chain fatty acids they produced.
They found that all five types of fiber significantly altered the animals’ gut microbiome and changed the levels of SCFAs they produced.
However, when they looked at body weight, fat mass, and glucose tolerance, only beta-glucan provided benefits.
MNT Chris Mohr, Ph.D., a registered dietitian and nutrition and fitness consultant at Fortune Recommends Health, wasn’t surprised to find that fiber improved health markers, but he was surprised to find that “only beta-glucan had a significant impact on weight gain and improved glucose tolerance.”
“It’s interesting to see such a distinct advantage for beta-glucan over the others in this particular study,” he said.
Susan Bowerman, a registered dietitian, senior director of global nutrition education and training for Herbalife and chair of Herbalife’s Dietary Advisory Board, was also surprised by the results, “especially since another soluble fiber, pectin, was also studied.”
There is a lot of evidence that supports the benefits of beta-glucan for heart health.
The U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) allow food manufacturers to make heart health claims on products containing beta-glucan.
However, its potential role in weight loss is less clear. While the results of this study are encouraging, it’s important to remember that what happens in mice doesn’t always happen in humans.
“Human metabolism and gut microbiota are more complex,” Mohr said. MNT“and individual responses to dietary changes may vary.”
“However,” he continued, “previous human studies have shown some benefits of beta-glucan, suggesting the potential for similar results, although further research is needed.”
This type of data can be difficult to collect and interpret. “To replicate this result in humans,” Bowerman says, “study subjects would have to follow a specific diet. Even if the results were proven, it’s hard to say how effective beta-glucan would be in a free-living population consuming a varied diet.”
It will probably take some time to understand how certain types of fiber affect health. However, we do know that a diet rich in fiber reduces the risk of disease and helps maintain a healthy weight.
We also know that around
“We don’t eat enough fruits, vegetables, beans and whole grains, which are the richest sources,” Bowerman says. “It’s important to include these foods in our daily lives.”
We asked the experts for advice on how to increase fiber intake.
“Eat more fruits and vegetables, as they are high in fiber and provide additional nutrients,” Mohr said. He also offered these tips:
- Choose whole grain bread, pasta and rice more often than refined versions.
- A simple and inexpensive way to add fiber is to simply add 1/2 cup of beans to your diet – foods like lentils, black beans, etc.
- Replace your current snacks with foods like nuts and seeds, which are high in fiber and provide healthy fats and protein.
- Stay hydrated, as fiber works best when it absorbs water.
Since many people in the United States consume only a very small amount of fiber, our experts recommend increasing your fiber intake slowly.
“Start slowly to avoid bloating symptoms – don’t go from zero to 25 grams per day,” Laster said.
MNT spoke with Nikky Contractor, Amway’s global head of research and development, who said that “too much food too quickly can lead to unwanted gastrointestinal symptoms, such as increased frequency of bowel movements, gas or bloating.”
The entrepreneur also reminded us that diversity is important: “Some microbiome scientists have indicated that we should consume as much of it as possible.
Changing your diet can seem daunting and difficult, but slow, gradual changes are likely to be more achievable. They will also be more effective than the latest fad diets and dangerous weight loss “hacks.”
While beta-glucan may one day become an evidence-based weight loss supplement, for now, focusing on vegetables, nuts, seeds, and whole grains is a good start.