High-Fibre Diet
Fibre doesn't get the glamorous attention of protein or the obsessive focus of carbs, but the evidence for its impact on health is staggering. Most people eat less than half the fibre they should, and the consequences reach far beyond digestion.
A high-fibre diet focuses on increasing the variety and amount of fibre-rich foods in daily meals, such as vegetables, fruits, legumes, nuts, seeds and wholegrains. Fibre plays an important role in digestion, blood sugar balance, gut microbiome health and overall wellbeing.
Rather than being a rigid plan, this approach encourages gentle increases in fibre intake through simple, sustainable changes. It supports the body by adding more of what many people already benefit from - plant diversity, colour and whole foods.
What is a high-fibre diet?
A high-fibre diet emphasises foods naturally rich in dietary fibre - the indigestible parts of plant foods that pass through your digestive system largely intact. Unlike other nutrients that are absorbed, fibre works its magic in your gut, where it feeds beneficial bacteria, slows digestion, absorbs water, and supports healthy bowel function.
High-fibre eating doesn't mean a special diet or expensive supplements. It means prioritising whole grains, legumes, vegetables, fruits, nuts, and seeds. Essentially, moving toward a more plant-rich approach. The current recommendation is 25–38 grams of fibre daily for adults, but most people consume only 10–15 grams.
What foods count as high fibre?
Whole grains - replace white bread, pasta, and rice with their whole-grain versions. Brown rice, oats, barley, quinoa, and whole wheat all provide significantly more fibre than refined versions.
Legumes - beans, lentils, and chickpeas are among the most fibre-dense foods available, providing 6–8 grams of fibre per cooked cup.
Vegetables - aim for 7–10 servings daily if possible. All vegetables contribute fibre, with particularly high amounts in leafy greens, broccoli, and root vegetables.
Fruits - berries, pears, apples, and avocados are fibre superstars. Eating the whole fruit (rather than juice) ensures you get the fibre.
Nuts and seeds - a small handful of almonds, chia seeds, or flaxseeds adds significant fibre and healthy fats.
If you're currently eating low fibre, jumping suddenly to high fibre can cause bloating and digestive upset. So increase gradually over 2–3 weeks as your microbiome adjusts. Alongside this, drink adequate water. Fibre works best when you're well-hydrated. Low water intake with high fibre can actually cause constipation.
What's the evidence surrounding fibre?
The evidence linking fibre intake to health outcomes is comprehensive and compelling.
Multiple studies confirm that increased fibre intake is one of the strongest predictors of weight loss, even more so than total calories or macronutrient ratios. This is because fibre slows digestion, increases satiety, and makes it easier to eat fewer calories without feeling deprived.
There are also incredible metabolic health benefits of a high-fibre diet. It's linked to lower cholesterol, lower blood pressure, and reduced cardiovascular disease risk. In particular, research shows that soluble fibre (found in oats, beans, and apples) actively lowers LDL ('bad') cholesterol. It also slows the absorption of carbohydrates, resulting in lower post-meal glucose spikes and more stable blood sugar overall. For people with type 2 diabetes, high-fibre diets often reduce the need for medication.
But the gut is where fibre's magic really happens. Different types of fibre feed different beneficial bacteria. A high-fibre diet supports a diverse, healthy microbiome, which has cascading benefits: better immunity, improved mood, reduced inflammation, and better metabolic health. Despite the myth that fibre causes bloating, adequate fibre intake actually prevents constipation and supports regular bowel movements. Initial bloating typically resolves within 2–3 weeks as your microbiome adapts.
Finally, people with the highest fibre intake have been found to have lower all-cause mortality - meaning they live longer and healthier lives than those with low fibre intake.
Different types of fibre have different benefits, which is why variety is key.
When is it helpful to focus on high-fibre?
A high-fibre approach is beneficial if you want to lose weight sustainably (and keep it off), have elevated cholestrol or increased risk of cardiovascular disease, have irregular bowel movements or constipation, have type 2 diabetes, experience cravings or energy crashes or generally want to support your gut health. It’s a flexible, accessible pattern suitable for most lifestyles.
Is any caution needed?
While high-fibre diets are generally safe, a few considerations apply:
Transition gradually - if you're currently eating low fibre, jumping suddenly to high fibre can cause bloating, gas, and digestive discomfort. Increase over 2–3 weeks, giving your microbiome time to adapt.
Ensure adequate hydration - fibre without sufficient water can worsen constipation. Drink plenty of water as you increase fibre.
If you have IBS or SIBO - some people with sensitive digestive systems struggle with high fibre or specific types of fibre. A lower FODMAP approach or working with a professional to identify tolerated fibres may be necessary.
With certain digestive conditions - if you have inflammatory bowel disease, diverticulitis, or other specific conditions, the type and amount of fibre may need adjustment. Work with your healthcare team.
Supplement quality matters - if using fibre supplements (like psyllium husks), ensure they're high-quality and used as an addition to, not a replacement for, whole-food fibre.
Nutritional therapists perspective
Fibre is perhaps the most underrated nutrient in modern nutrition. It doesn't have the sexy appeal of protein or the restriction of low-carb eating, but its impact is profound because fibre is foundational to nearly every health goal.
Better weight management? Fibre helps.
Stable blood sugar? Fibre is central.
Healthy gut? Fibre feeds the bacteria that keep it healthy.
Clear skin? Often improves with better gut health, supported by fibre.
Stable mood? The gut-brain connection is real, supported by fibre.
The challenge is that whole plant foods, where fibre lives, have fallen out of favour in modern eating. We've become accustomed to white bread, peeled fruits, and refined grains. Going back to whole foods feels like a step backward, but it's actually a return to the way humans have eaten for millennia.
If you implement just one dietary change, making it about fibre - gradually increasing your intake through whole foods - is one of the most impactful things you can do. The evidence is clear, and most people feel noticeably better within weeks.
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Many people try increasing fibre to support digestion or energy, but symptoms don’t always improve as expected. If you’re experiencing bloating, discomfort or irregularity and aren’t sure how to adjust things safely, personalised nutrition can help identify what’s influencing your symptoms - and how to support your gut gently.
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