Did you know fibre impacts weight management? To understand how to define dietary fibre it is important to know that there is no single accepted definition of dietary fibre but a physiologically based description is dietary constituents that are not enzymatically degraded to absorbable subunits in the stomach and small intestine.
Eat more, weigh less? The surprising truth about fiber and fat loss
In an interview with HT Lifestyle, Dr Navneet Deora, PhD in Food at Bluetribe, shared, “Due to the nature of fibres in terms of its functionality and solubility in water it can be broadly classified as soluble or insoluble and fermentable or non-fermentable. Solubility depends on the extent to which the fibre dissolves in water or forms a gel. Fermentability relates to whether the undigested fibres that reach the large intestine are fermented by anaerobic bacteria to yield short-chain fatty acids and gases such as methane and hydrogen. The type of fibre does play a critical role in the area of weight management.”
Substantial research has been conducted to ascertain the relationship between fibre and weight management and typically it shows an inverse relationship between dietary fibre intake and change in body weight. Dr Navneet Deora explained, “Dietary fibre’s ability to decrease body weight or attenuate weight gain could be attributed to several factors. Under conditions of fixed energy intake, the majority of studies indicate that an increase in either soluble or insoluble fibre intake increases post-meal satiety and decreases subsequent hunger.”
What fiber really does to your body
Dr Navneet Deora elaborated, “For example, soluble fibre, when fermented in the large intestine, produces glucagon-like peptides and peptides. These two gut hormones play a role inducing satiety. Second, dietary fibre may significantly decrease energy intake. It is important to understand that dietary fibre still contributes to the total caloric content of a diet, it is much more resistant to digestion by the small intestine and even somewhat resistant in the large intestine.”
According to the expert, consumption of insoluble fibre decreases energy digestibility while it increases with soluble fibre intake. Dr Navneet Deora said, “The mode of action behind these findings may be due to the fact that insoluble fibre causes an increased rate of passage through the GI tract. This would be expected to result in diminished digestion and absorption of nutrients. This both soluble and insoluble fibre may lead to weight loss.”
However, there seems to be a relationship between the type of diet (high or low fat) and the type of fibre consumed. Dr Navneet Deora highlighted, “Insoluble fibre may play a more important role for weight loss during consumption of a high fat diet. Since resistant starch is a constituent of dietary fibre and undergoes the same digestion as insoluble fibre, comparing resistant starch and insoluble fibre may give us a better understanding of how dietary fibre can be used to treat and prevent obesity. Thus, although increasing dietary fibre in general has a favourable effect on body weight, more research is warranted to determine the optimal dietary fibres for the purpose of weight management.”
The American Heart Association Eating Plan suggests aiming for 25 to 30 grams of dietary fibre daily from food sources which translates to aprox 14 g/1000 kcal in children and adults. Dr Navneet Deora opined, “The diets with a high content of fibre, such as those rich in cereals, fruits and vegetables have a positive effect on health since their consumption has been related to a decreased incidence of several types of diseases.”
He concluded, “Its beneficial effects are decreasing the time of intestinal transit, cholesterol and glycaemic levels, trapping substances that can be dangerous for the human organism (mutagenic and carcinogenic agents), stimulating the proliferation of the intestinal flora etc. Diets can have a variety of fibre rich foods (both soluble and insoluble) such as wheat straw, oats, soy bran, rice bran, apples, legumes, mucilaginous fibre.”
Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.
