We eat too little dietary fibre
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Most people still know it under the term "roughage". However, dietary fibre is far more than just the ballast substance of food - it also has important functions. Nevertheless, its consumption in Switzerland is too low.
In science, everything originally revolved around calories, proteins, carbohydrates and fats. This was later followed by an interest in micronutrients, minerals and vitamins, before attention was finally paid to dietary fibre. The first scientific reports on dietary fibre appeared in the mid-1950s, even though its essential effects were not understood at that time. Back then, it was still believed that dietary fibre was completely indigestible and had practically no nutritional value. However, enough dietary fibre would ensure a suitable mass to the stool and thus improve emptying. That is why dietary fibre was originally called "roughage".
Burkitt's hypothesis
In the 1960s, the opinion on dietary fibre changed. More and more people suspected a preventive effect in various diseases, including cancer, cardiovascular and intestinal diseases. This hypothesis on the preventive effect of dietary fibre is named after one of the researchers, who was one of the first to express his opinion on this connection: Denis Burkitt.
Burkitt's hypothesis on the negative side effects of a diet with too little fibre is now confirmed. A low intake of dietary fibre is now undoubtedly considered a risk factor for many diseases such as colon, liver and breast cancer, as well as for the entire cancer mortality rate, cardiovascular disease and diabetes.
How much is optimal?
How much dietary fibre do we actually need? In Europe, adults have a reference value of 25 grammes of dietary fibre per day. However, this recommendation only reflects the amount that is necessary for a normal bowel movement, i.e. according to the original meaning of dietary fibre as "roughage". The Swiss reference value of at least 30 grammes per day is therefore not very different from the European value.
The extent to which the additional effects of dietary fibre can benefit us at these quantities has not yet been conclusively clarified. One thing is certain: traditional diets contain far more dietary fibre than 25 to 30 grammes. For example, in rural South Africa with an original diet, the intake is between 50 and 90 grammes per day, and a follow-up analysis of the traditional Mediterranean diet in Crete came in at just under 50 grammes per day. In addition, it is believed that our ancestors, who lived about 50 to 100,000 years ago, consumed more than 100 grammes of dietary fibre per day. The Swiss recommendation of around 30 grammes per day therefore appears to be a minimal rather than an optimal intake.
Modest consumption in industrialised nations
Around ten years ago, food consumption was analysed for the first – and so far only - time in Switzerland. The evaluation of dietary fibre was only carried out in 2024! According to the national consumption study menuCH, dietary fibre consumption was around 19 grammes per day among 18 to 75-year-olds. 87 percent of adults had a lower consumption than the Swiss recommendation of at least 30 grammes per day. The consumption of dietary fibre also correlated negatively and dose-dependent with the consumption of highly processed products. That is why the researchers who conducted the evaluation demanded that measures be taken in the interest of public health to increase the consumption of dietary fibre and promote a lower consumption of highly processed products.
It is not clear why dietary fibre has not received the same attention in public health as salt or sugar. Even the justification that the focus is on salt and sugar reduction, because these recommendations are supported by the WHO, is not valid. Indeed, even the WHO correctly recommends promoting the consumption of dietary fibre.
Dietary fibre in sports
In contrast to carbohydrates or proteins, for example, there is no separate assessment of dietary fibre in sports. It is therefore basically the same as for the general population. Due to its effect as feed for the microbiota, dietary fibre is also considered a basic component of a meaningful diet in sports. In addition, there is the presumption of potentially improved performance with "satisfied" microbiota and optimal intestinal health. Too little dietary fibre must therefore be considered not only as suboptimal for sports health, but also as potentially performance-reducing.
The only exception is to avoid too much dietary fibre shortly before and during intensive exercise as this may lead to digestive problems. Otherwise, plenty of dietary fibre is generally part of a healthy sports diet.
Nuts, legumes, whole grains
If you want to increase your consumption of dietary fibre, you should integrate various foods into your diet. These primarily include nuts, legumes and whole grains. However, legumes should not be considered a source of protein, since their protein quality is modest. An increased consumption of legumes at the expense of a lower consumption of animal protein sources would therefore be counterproductive for muscle health.
*Nutritional expert Dr Paolo Colombani is a scientific consultant with his own company. Together with Dipl. Ing. ETH Christof Mannhart, he runs "Notabene Nutrition”, the online magazine with well-founded articles on foods, supplements & healthy living. www.colombani.ch; www.notabenenutrition.media
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