Fibre: The 30g Minimum
The UK National Diet and Nutrition Survey consistently shows that the average adult consumes around 18g of fibre per day. The official recommendation is 30g. This 12g deficit is the root cause of widespread digestive issues, poor satiety, and elevated cardiovascular risk.
Why 30g? The Data
A landmark 2019 review published in The Lancet by Reynolds et al. analysed nearly 40 years of data. They found that individuals consuming between 25g and 29g of fibre daily saw a 15-30% decrease in all-cause and cardiovascular related mortality compared to those consuming the lowest amounts. The benefits continued to increase with intakes exceeding 30g.
Soluble Fibre
Dissolves in water to form a gel-like substance. It slows gastric emptying, which keeps you fuller for longer and blunts blood sugar spikes.
Best Sources: Oats, beans, apples, carrots, barley.
Insoluble Fibre
Does not dissolve in water. It adds bulk to the stool and helps food pass more quickly through the stomach and intestines.
Best Sources: Whole wheat flour, wheat bran, nuts, cauliflower.
The High-Protein Pitfall
Many individuals adopting a high-protein diet inadvertently drastically reduce their fibre intake by replacing complex carbohydrates (like lentils and oats) with animal proteins (which contain zero fibre) and highly processed protein powders. This leads to the infamous "meat sweats" and severe constipation.
To avoid this, you must consciously integrate high-fibre foods into your diet. For ideas on how to do this, check out our guide on High Fibre Snacks.
Common Mistakes When Increasing Fibre
- Going too fast: Jumping from 15g to 40g overnight will cause severe bloating and gas. Increase by 5g per week.
- Forgetting water: Fibre needs water to move through the digestive tract. If you increase fibre without increasing water intake, you will become constipated.
- Relying entirely on supplements: While psyllium husk is great, relying solely on it robs your gut microbiome of the diverse plant materials it needs to thrive. Read more about Soluble vs Insoluble fibre.
Frequently Asked Questions
Is it possible to eat too much fibre?
Yes. Intakes exceeding 70g per day can interfere with the absorption of essential minerals like calcium, iron, and zinc due to the binding properties of certain fibres. It can also cause severe gastrointestinal distress.
Does blending fruit destroy the fibre?
No, blending does not destroy fibre. However, it pulverises the structural integrity of the plant cells, which means the sugar is absorbed much faster than if you ate the fruit whole. Juicing, on the other hand, actively removes the insoluble fibre.
Track Your Fibre
Use our tool to calculate your exact fibre target based on your caloric intake.
Go to Fibre Calculator