Focus on Fibre
There’s a lot of fuss about protein, with a new ball, bar or powder seemingly launched every day.
But the reality is that most people already eat more than enough of it.
Your required intake does depend on your size and fitness goals. But major national surveys indicate that, on average, we eat 44% (females) to 52% (males) more protein than the guideline daily amounts .
In fact, the only macronutrient we don’t eat enough of is fibre, which could be critical for our health.
According to the NHS, there’s strong evidence that eating plenty of fibre is associated with a lower risk of heart disease, stroke, type 2 diabetes and bowel cancer .
eating plenty of fibre is associated with a lower risk of heart disease, stroke, type 2 diabetes and bowel cancer
And whilst most people know that fibre helps keep you regular, you may not know that constipation has been linked to Parkinson’s disease . Or that it’s often a symptom of colon cancer. Studies indicate a 43% reduction in risk of colon cancer for people eating the most fibre versus those eating the least .
Taking a closer look, fibre’s either soluble (broken down by the bacteria in our guts, with some of it being digested) or insoluble (hardly broken down or digested). Because relatively little of it digested, it’s judged to contain 2 calories per gram, compared to 4 for carbs and protein and 9 for fat.
Soluble fibre forms a gel-like substance once broken down, which attaches to cholesterol and removes it from the body  . It also slows down the entry of glucose into the blood, improving blood sugar levels . Indeed, increasing fibre intake has been shown to help diabetics better control their blood glucose .
Just as importantly, soluble fibre contains prebiotics that promote the growth of healthy bacteria in your gut (probiotics). These are increasingly seen as a key determinant of our health, and use the fibre as a food source. They turn it into short chain fatty acids that limit the growth of bad bacteria and help improve mineral absorption .
The 2015 US Dietary Guidelines Advisory Committee noted that a reduction in the diversity of our microbiomes is generally associated with poor health outcomes – disruption of the normal balance has been associated with obesity, malnutrition, bowel disorders, neurological disorders and cancer . And it noted that the reduction in microbiome diversity has accompanied a decline in fibre intake .
reduction in microbiome diversity has accompanied a decline in fibre intake
Unsurprisingly, therefore, more and more research supports a daily high fibre diet as the most powerful approach to improving microbial communities in our gut, rather than taking probiotic supplements, because fibre’s their meal of choice .
Insoluble fibre passes through our bodies largely unchanged. but it does help detox us, removing things like lead and mercury . Our bodies are used to and need a constant flow of soluble and insoluble fibre to help them clean themselves.
Along with soluble fibre it also helps make us feel full, which can help considerably with weight loss. Studies show that people simply adding more fibre to their normal diets lose almost as much weight as those following specific low-fat eating plans. And the high fibre diet was easier to stick to than the more structured alternative . This is probably because the stomach tells the brain to stop eating after a certain volume of food has been ingested. When much of that volume is a low or zero calorie component like fibre or water, you can eat more food but gain less weight .
Naturally high fibre foods also require more chewing. This burns calories and gives your brain longer to register feelings of fullness, meaning you’re less likely to overeat.
And because it’s relatively hard to digest, fibre also helps make you feel fuller for longer .
At least some of the benefits of fibre may be down to the micronutrients that are bound to it . Most of these are non-extractable, which means they’re not absorbed or metabolised by the stomach (small intestine) . Instead they’re broken down by the gut bacteria in the colon (large intestine).
At least some of the benefits of fibre may be down to the micronutrients like polyphenols that are bound to it
It’s relatively easy to distinguish between soluble and insoluble fibre. But “fibre” actually represents hundreds of substances that operate through an exceptionally complex series of biochemical and physiological events. And it’s virtually impossible to know what each sub-fraction does in the body .
So the precise relationship between fibre and health is still being researched. But when you take all the above into consideration, it’s no surprise research has found that “those who had the highest intake of fibre…had an almost 80% greater likelihood of living a long and healthy life over a 10-year follow-up” .
Similarly, studies into African diets in the 1960s and ‘70s noted the significantly larger intake of fibre by Africans relative to Westerners (60-140g vs 20g per day) and their coincident lack of Western diseases such as diabetes and heart disease .
According to the NHS, however, whilst adults should aim for 30g of fibre a day, most people only get 18g .
That’s 40% less than ideal, and the 30g recommendation is probably on the low side given everything noted above.
Indeed, evidence suggests at least 70g a day is needed to help prevent strokes in particular . And that it’s never too early to increase your intake. Artery stiffening (associated with low fibre intake) starts well before you start to see symptoms, for instance .
evidence suggests at least 70g a day is needed to help prevent strokes in particular
So why do we eat so little fibre?
Probably because we’re now eating less and less unprocessed plant foods. Instead we’re relying on refined / highly processed grains and carbs, and more and more animal based products. Refined carbs typically have the fibre stripped from them during processing, and animal based products contain almost no fibre.
Fruit juices in particular are a good example. Although they’re nutritious in that they contain vitamins, minerals and polyphenols etc, they basically contain no fibre. And evidence suggests that this results in other nutrients being stripped out too. So whilst they’re very convenient, and probably not bad in moderation, they’re no substitute for eating an actual apple. Our future blogs on sugar and whole foods will discuss juices more.
Convenience definitely plays a part elsewhere too. With our increasingly hectic lifestyles, it’s ever harder to find time to prepare healthy, whole food snacks and meals.
the general trend to more convenient, processed food is exacerbated by diets focused on higher fat or protein but lower carb dishes
And the general trend to more convenient, processed food is exacerbated by diets focused on lower carb dishes. This often results in less fibre being consumed. We’re all for ditching bad carbs like free sugars and refined grains. But it’s essential not to neglect the good ones, which include fruit and veg!
What can we do about it?
Overall, as expressed recently by the British Nutrition Foundation, “fibre is a nutrient where not enough attention has been paid”. That needs to change.
Fortunately, however, it does seem to be happening. A recent industry article concluded that fibre’s time in the limelight could now have arrived, for instance. It attributed it to the scale and importance of the nation’s obesity problem in particular .
More importantly, an increasing number of high fibre products (and supplements) are coming to market.
Most of these are based on chicory root fibre (inulin) or other processed fibres like fructo-oligosaccharides though, rather than high fibre whole foods.
Such processed fibres have benefits in that they’re particularly high in prebiotics. But they’re high FODMAP , so can cause digestive distress. And there’s little evidence that adding them to food has the same effect as eating foods naturally high in fibre .
Even companies using processed fibres state that they shouldn’t be used as a replacement for whole foods high in fibre
Indeed, the American Institute for Cancer Research believes you shouldn’t view chicory root / inulin as healthy alternatives to whole foods. Because whole foods give you not only fibre, but also a vast selection of phytochemicals. Even companies using processed fibres state that they shouldn’t be used as a replacement for whole foods high in fibre .
Putting it bluntly, the Center for Science in the Public Interest comments that “The food industry has hijacked the advice to eat more fiber by putting isolated, highly processed fiber into what are essentially junk foods”. Dr. David Ludwig of the Harvard School of Public Health adds: “Highly processed snack bars typically contain combinations of processed starch and added sugar. They’re low in vitamins and minerals…Just adding isolated fiber back in does not cover up for those nutritional deficiencies” .
Because of the complex relationships referred to earlier, it’s hard to see how isolated fibres (including fibre supplements) could be as beneficial as whole plant foods that are naturally high in fibre. Indeed, whole grain fibre has been found to be more beneficial than the same amount of refined grain fibre . This supports the idea that elements botanically linked to fibre may confer important health benefits above and beyond the effects of the fibre itself .
In summary, there’s no substitute for eating more whole foods like fruit and veg (not juices or smoothies), nuts, beans and whole grains, all of which are naturally high in fibre. And this includes prebiotic fibre. Although chicory root is particularly high in inulin, it can apparently be found in 36,000 different plants. So there’s no need to supplement with added fibres if you already have a balanced diet.
As with other areas of diet / nutrition, try to eat as wide a variety of high fibre foods as possible. It’s the best way to ensure that you get as wide a variety of other nutrients too.
there’s no substitute for eating more whole foods like fruit and veg, nuts, beans and whole grains
It’s easy to grab a piece of fruit or some nuts. But it can be hard to incorporate a lot of veg into a busy schedule. And certainly in a tasty way! Given that they’re typically higher in fibre and lower in sugar than fruit, that’s a real shame.
So that’s why we developed the Veggie Bar, which is launching soon.
Made with c70% veg, which is naturally high in both soluble and insoluble fibre, each bar will have at least 4g of whole food fibre and will be two of your five a day (see our earlier blog about the power of veg here), with nothing artificial.
Available in a range of enticing flavours, they’re a tasty and easy way of naturally eating more fibre, helping you to lead a healthier, happier life.
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