Top Fibers for Weight Loss: Studies Reveal Not All Are Created Equal

Maintaining a healthy weight is not only important for good health, but also benefits emotional wellbeing and personal confidence, this is why weight management is an important issue for most women.

Research on the gut microbiome has triggered a revolution in nutritional science and in the last few years, dietary fibre has become the new protein, added to food to feed our gut and boost our health.

• A recent study however suggests that not all fibre supplements are equally beneficial. The study confirmed that beta-glucan which is readily found in oats and barley can control blood sugar and assist in weight loss when tested on mice who were fed a high-fat diet.

• Researchers at the University of Arizona and the University of Vienna both confirmed that the only type of fibre supplement they tested that decreased fat content and body weight within 18 weeks was beta-glucan from oats and barley.

• The other fibres considered including wheat dextrin, pectin and resistant starch did not contribute to weight loss.

Dietary fibres are the main source of energy for bacteria living in our guts, and yet less than five per cent of people in Australia consume the recommended 25-30 grams of fibre a day.

• To make up for this deficiency there is a growing consumer intake of fibre supplements, but fibres are extremely diverse, so which one do we choose?

• Some fibres like oat beta-glucans and wheat dextrin are water-soluble, meaning they are easily fermented by gut bacteria. Others, like cellulose and resistant starch, are less soluble or insoluble, meaning they stick to other materials to form stool.

In the past, biomedical researchers had not investigated the role of various fibres in one cohort. However, recently a study tested several forms of fibre in one cohort. Only beta-glucan was found to increase the number of Ileibacterium found in the intestine of the mice on which the test was performed.

• Other studies on mice have also linked this bacterium to weight loss. Sure enough, long before the 10-week marker, mice fed beta-glucan showed reduced body weight and body fat content compared to those fed other fibre forms.

• The findings align with another recent study that fed barley floor, rich in beta-glucan, to rodents. Even though the rats continued eating just as much of their high-fat diet as before, their energy expenditure increased, and they lost weight anyway.

A similar outcome was observed in mice fed beta-glucan in a new study.

• These animals also showed increased concentration of butyrate in their guts, which is a metabolite made when microbes break down fibre.
• Butyrate induces the release of glucagon-like peptide-1 (GLP-1), which is the natural protein that synthetic drugs like Ozempic mimic to stimulate insulin release.

• Part of the benefit of consuming dietary fibre is through the release of GLP-1 and other gut peptides that regulate appetite and body weight.

• However, scientists don’t believe that that is the only effect.
• They think that there are other beneficial things that butyrate could be doing that are not gut peptide related, such as improving gut barrier health and targeting peripheral organs like the liver.

Further research is needed before these results can be extended to humans, but the findings suggest that some fibres may be better suited to weight loss and insulin control than others.