Fibre: The Key Nutrient for Digestion, Weight Loss & Cholesterol
For women navigating weight management, gut health and cholesterol, fibre may be the key macronutrient which is missing. Most women fall short of the recommended 25–30g of fibre a day, barely making even half of that. And this impacts your health in many ways.
What Is Fibre
Fibre comes in two forms, and you want both:
Soluble fibre dissolves in water and forms a gel-like substance in your gut. Found in oats, chia seeds, flaxseeds, lentils/legumes, apples, pears, barley and psyllium.
Insoluble fibre doesn't dissolve — it adds bulk and helps things move through your digestive system. Found in wheat bran, whole-grains like brown rice and quinoa, vegetable skins, kiwi fruit, berries, nuts and seeds.
Most whole plant foods contain a mix of both, which is why eating a variety of plant based foods is beneficial to your health, so you get a nice balance!
Fibre and Weight Management
Fibre supports weight loss in a few ways:
Slows gastric emptying. Soluble fibre forms a gel in the stomach that slows how quickly food moves through your digestive tract, which extends feelings of fullness after a meal. And therefore reducing hunger and overeating.
Increases satiety with low calories. High-fibre foods tend to be more filling for fewer calories than heavily processed alternatives, which naturally supports portion control without restrictive dieting.
Our microbiome improves metabolic health. When fibre reaches the large intestine, gut bacteria ferment it into short-chain fatty acids (SCFAs) like butyrate. SCFAs can help regulate signalling of our appetite hormones, again reducing hunger and improving satiety.
Fibre is a great way to feel satisfied with very little calories, and added benefits!
Fibre and Gut health
This is where fibre really shines. Fibre is essentially the fuel source for your gut microbiome. When you eat a variety of fibre-rich plants, you're feeding a diverse range of beneficial bacteria, which:
Produce SCFAs that help maintain the gut lining
Support regular bowel movements, preventing constipation
Modulate inflammation in the body
Play a role in immune function, with 70% of your immune system living in your gut
Our microbiome needs diversity, so eating a variety of different plant foods is most beneficial to our gut health!
Fibre and Cholesterol
This is where I see our microbiome and diet impact people’s health the most - rising cholesterol levels despite eating a “healthy diet.”
Soluble fibre plays a direct role in cholesterol management through a process called bile acid binding:
Your liver uses cholesterol to make bile acids, which are needed for digesting fat.
Soluble fibre binds to these bile acids in your gut and carries them out of the body.
To replace the lost bile acids, your liver pulls more cholesterol out of your bloodstream — specifically LDL ("bad") cholesterol.
So with adequate soluble fibre intake, we see a reduction in LDL cholesterol.
Practical ways to add more fibre this week
You don't need to overhaul your diet. A few small swaps add up fast:
Swap the pasta for lentils or quinoa
Add a tablespoon of chia or ground flaxseed to porridge, smoothies or yoghurt
Add a handful of greens like spinach leaves to your smoothie
Snack on raw carrot sticks with hummus instead of rice crackers
Leave the skin on fruit and vegetables - e.g. eat the whole kiwi fruit, natures laxative!
Add a tin of beans or lentils to soups, curries and bolognese
Increase fibre gradually and drink plenty of water alongside it — a sudden jump can cause bloating.
If you don’t tolerate fibre well, there could be some underlying gut dysfunction such as low stomach acid,, Dysbiosis or SIBO, where certain fibres can actually flare gut symptoms. In this case you want to work with your healthcare practitioner to resolve the underlying imbalance.
