The history of fibre and fat loss
Fibre has long been understood to support fat loss and overall weight management. It’s mechanisms in doing so are more mechanical than hormonal, but with most functions in the human body there is of course some overlap here. Fibre is also known as Non- starch polysaccharides, which basically refers to the non- starch components of a plant based structure. Non- starch polysaccharides are found in the cell walls of vegetables, fruits, pulses and cereal grains, so when forming part of the human diet this nutritional component is known as FIBRE.
How fibre helps fat loss
Fibre is great for overall health and well being, it can reduce cholesterol in the body and improve your cholesterol ratio (good to bad cholesterol). Fibre can also reduce the amount of fat your body actually absorbs, as well as reducing the physical space available in the stomach. Moreover, good sources of fibre such as green leafy veg and wholegrains are low in calories and make for good space fillers on your plate too, reducing the space available for additional calories.
Different types of fibre
There are two main types of fibre, soluble and insoluble fibre, and this basically refers to how well the fibre mixes with water. Soluble fibre, for example, mixes very well with water and is capable of absorbing the fluid in the bowel (digestive tract) helping to thicken the stool (poo). Too much soluble fibre can also clog you, so it’s important to get the balance between soluble and insoluble fibre right. Insoluble fibre does not mix well with water, it generally has an impermeable outer layer meaning it repels water. Consequently the water in the bowel has no where to go resulting in a more watery stool…get the balance right and you can achieve an optimal stool consistency making it easier to go to the toilet and clear waste.
The presence of optimal ratios of fibre in the bowel increases the transit rate of waste, and therefore fat, through the body. The faster the foodstuff/ waste passes through the bowel the less time there is for fat to be absorbed into the body, resulting in a greater output of fat during excretion.
Revelations in how fibre suppresses appetite
Recently an international team of researchers identified an anti-appetite molecule in fibre known as acetate. This molecule is naturally released when fibre is digested in the gut, once released the acetate is transported to the brain signalling it to stop the need to eat. This finding reinforces the need to increase fibre in the UK diet as a means of controlling over eating and excessive weight gain. The researchers even found that if acetate was added to the bloodstream, the colon or the brain, that it reduced appetite every time.
Professor Gary Frost, from the Department of Medicine at Imperial College London states:
"In stone-age times we ate about 100g [of fibre] per day but now we favour low-fiber ready-made meals over vegetables, pulses and other sources of fiber. Unfortunately our digestive system has not yet evolved to deal with this modern diet and this mismatch contributes to the current obesity epidemic. Our research has shown that the release of acetate is central to how fiber supresses our appetite and this could help scientists to tackle overeating."
So without doubt, the UK population should be aiming to increase their current intake of approx 15g of fibre to a minimum of 18g a day, and this should be comprised of a mixture of both soluble and insoluble sources for best results.
Food Standards Agency, (2008). Manual of Nutrition. 11th Ed. Non-starch polysaccharides. London: TSO
ScienceDaily, (2014). Discovery of anti-appetite molecule released by fiber could help tackle obesity. Retrieved 6th May, 2014, from http://www.sciencedaily.com/releases/2014/04/140430083031.htm