Why You Need to Eat High Fibre Foods
Many people are aware fibre is good for them but the reasons why may be far wider reaching than you’d think. Fibre comes in two main types – soluble and insoluble fibre. Soluble fibre is categorised by the fact it is soluble in water, whereas insoluble fibre is not. Soluble and insoluble fibres are classified as indigestible fibre as they’re both resistant to digestion in the small intestine. Instead, they pass through into our colon, which is also known as the large intestine and often referred to as the gut. It is here that fibre plays a key role in maintaining gut health.
As these forms of fibre are resistant to digestion they do not contribute, at least not significantly, to our energy intake. This means high fibre foods are great for weight loss because they often provide a feeling of fullness without much of a calorie cost. High fibre diets are also associated with better hunger control when dieting and improved weight loss outcomes.
Fibre also slows the breakdown of the digestible, starchy parts in carbohydrate rich foods, which in turn slows down the rate of glucose entering the bloodstream. All starchy carbohydrates are broken down into glucose before being taken up through the small intestine and used in the body for energy. A more steady supply of glucose caused by the presence of fibre in a meal might help to support a more sustained energy supply, which may help prevent cravings and crashes in energy.
RECOMMENDED FIBRE INTAKE
Recommended intakes for total fibre are around 25-30g per day. This amount has been associated with reduced risk of several types of cancer and cardiovascular disease. This is because our gut is intrinsically linked to our immune system in several, what might be surprising, ways… and this is linked to our ‘good’ gut bacteria.
This is where soluble fibre really comes into its own. Within our colon, there are literally thousands of different species of bacteria and trillions of organisms. This is collectively known as our microbiota, and these bacteria are much more essential than many people realise. Soluble fibre is an essential fuel source for these bacteria to proliferate and feed, and it is during this feeding process that the fermentation of soluble fibre produces short chain fatty acids (SCFA’s).
FIBRE AND SHORT CHAIN FATTY ACIDS
SCFA’s are important because they are a preferred fuel source for parts of your digestive system and immune system. Providing the cells that line your gut with their preferred fuel source means they will create a strong barrier and work more effectively at preventing any unwanted pathogens entering the body, assisted by other bi-products from the fermentation of fibre. This also helps create an environment where pathogens struggle to survive.
In addition to helping create an anti-pathogen barrier and environment, more recent research is starting show these SCFA’s – particularly one called butyrate – have wider reaching immune system functions. One of these functions is in the development and behaviour of cells that ‘seek and destroy’ unwanted invaders in the blood stream. Emerging evidence even suggests our skin, an essential external barrier to unwanted pollutants, bacteria and viruses, is supported in its function by butyrate, with several other SCFA’s produced by bacteria potentially being important in a wide range of immune system processes.
FIBRE AND COGNITIVE FUNCTION
Beyond the immune system, there is increasing recognition SCFA’s play an important role in cognitive function through what is known as the gut-neurological axis. This ‘axis’ is a pathway that our gut, and the bi-products of bacterial fermentation, interact with our brain. This is a fascinating area of research with evidence linking gut health to several cognitive disorders including autism, depression and even Parkinson’s disease. Although this research is far from conclusive at present, it does give a tantalising insight into the interactions between our gut and the overall health of our body.
MORE THAN REGULAR BATHROOM BREAKS
Fibre, therefore, is so much more than simply keeping us ‘regular’ in the bathroom and it really should be given the attention in the diet that it deserves. There are plenty of high fibre foods including oats, whole grain rice/pasta, wheat bran, nuts and seeds, ‘greens’ such as broccoli and spinach, fruits such as dates, figs and apples and even avocados also contain a good amount of fibre per serving.
For weight loss or maintaining a healthy weight, although our energy balance (the amount of calories we consume compared to the amount we expend) is the most important factor, it is still important to think about where we get these calories from to promote overall health. As processed foods and refined grains contain less fibre, it is important to try to make a conscious effort on eating more whole foods. This will not only help us provide enough fibre, but also other essential vitamins and minerals that many people are often deficient in. The added bonus is that these foods will also make weight loss and maintaining a healthy weight ‘easier’ due to the ‘filling’ nature of high fibre, nutrient dense, low calorie and high volume foods.
One popular way to ensure we get enough fibre and other important vitamins and minerals is by drinking smoothies. But remember to leave in the pulp (that’s the fibre!) and be aware that calories can rack up quickly if you’re not careful with the type and amount of fruit it contains. Unfortunately, the calories do still count even from ‘healthy’ foods and it is much easier to drink calories than to eat them. However, with the wide variety of high fibre foods available, it shouldn’t take too much effort to hit your daily fibre goals with a small amount of thought. This can easily be achieved by ensuring each meal contains a portion or two of vegetables, choosing whole grain carbohydrates over more refined grains and adding a couple of pieces of fruit to our daily routine.