Protein and fibre: why women need both, and how to get the balance right
- Jun 3
- 4 min read
If you've been paying attention to nutrition over the last couple of years, you will have noticed how much attention protein and fibre are both getting, with podcasts, Instagram and health newsletters championing one or the other, telling you to prioritise protein, then to load up on plants, then to focus on fibre. After a while it becomes genuinely hard to know what's good for your own body, because the amount of each that helps you feel your best varies from one person to the next, and that confusion is a sign that the advice was never written with you in mind.
Why this keeps coming up in clinic
I work with women who are already trying hard, reading a lot on the topic, eating thoughtfully, and still feeling like something is not quite adding up.
Two clients recently brought this into sharp focus for me. One had been eating a vegetarian diet and putting real effort into her nutrition, but protein had slipped through the gaps, and she could not work out why she still felt off. Another had gone the other way, focusing hard on hitting her protein targets, and had gradually crowded out the fibre and plant variety her gut needed.
On the surface these look like opposite problems, and in a sense they are, but both come down to the same thing which is a balance between protein and fibre that had tipped too far one way.
What is happening in your body
Your body needs protein and fibre for very different reasons, and both matter more than most people realise.
Protein digestion starts in the stomach, where acid and the enzyme pepsin begin breaking it down. It is completed in the small intestine, where pancreatic enzymes and enzymes lining the gut wall break proteins into amino acids. These amino acids are then absorbed and used to build and repair tissues, produce hormones, support immune function, and help promote satiety and more stable energy levels throughout the day.
Fibre takes a different path. It travels largely intact to the colon, where your gut microbes ferment it and produce compounds that help maintain your gut lining, regulate inflammation, influence your mood, and affect your appetite. When too much protein consistently arrives in the colon without enough fibre alongside it, the environment in your gut can shift in ways that show up in how you feel over time.
Rather than competing for space in your diet, protein and fibre are designed to work together.
Signs your protein and fibre balance might be off
If your protein and fibre intake are out of sync, you might notice some of the following:
• Low or unpredictable energy across the day
• Bloating or digestive discomfort, particularly after meals
• Constipation or irregular bowel movements
• Frequent hunger or cravings, especially in the afternoon
• Difficulty maintaining or building muscle despite regular exercise
• Brain fog or trouble staying focused
• Skin that feels dull, congested, or slow to heal
• Mood dips or feeling low without an obvious reason
• Feeling sluggish rather than satisfied after eating
None of these symptoms are diagnostic on their own, and there are many reasons they can occur, but if several of them feel familiar to you, the balance of protein and fibre in your diet is worth looking at.
How I work out the right balance with each client
When I work with someone on this, I am not only looking at what they are eating. I am looking at the whole picture including their health history, how their digestion is working, where their energy dips are happening, and what else might be contributing.
Getting the balance right looks different from one woman to the next. A woman in her 40s who is perimenopausal, works full time, and barely has a moment to think about lunch has different needs to a woman in her late twenties who is training regularly and eating a plant-based diet. The numbers below are a starting point, not a prescription.
Can functional testing help uncover what's driving your symptoms?
For some women, dietary changes alone are enough to make a noticeable difference. For others, particularly those with persistent digestive symptoms, longstanding fatigue, or symptoms that do not seem to respond to what they are eating, looking more closely at what is going on can be genuinely useful.
The functional testing I use in clinic includes comprehensive stool analysis to assess gut microbiome health and digestive function, blood testing to identify specific nutrient deficiencies, and, where bloating or gut symptoms are a prominent feature, testing to rule out bacterial overgrowth. Testing is never the starting point, but it can help us understand what is driving the symptoms rather than guessing.
Three practical places to start
1. Aim for 1.2 to 1.6g of protein per kg of body weight each day. This varies with your age, activity level, and what else is going on for you, so treat it as a guide rather than a hard rule, and spread it across your meals rather than loading it into one sitting.
2. Aim for 30g of fibre daily from a wide variety of whole plant foods. Wholegrains, legumes, vegetables, fruits, nuts, and seeds all count, and diversity matters just as much as quantity, so vary what you are eating rather than relying on the same few foods.
3. Track what you eat for a few days to find your baseline. Not forever, and not obsessively, just for three to five days, so you can see where things stand before changing anything. Most people are surprised by what they find.
Ready to understand what is going on for you?
If you have been trying to figure this out on your own and still feel like something is not quite right, you do not have to keep piecing it together from conflicting sources.
As a BANT registered nutritional therapist, I work with women to investigate what is driving their symptoms and build a clear, personalised way forward.
A free discovery call is a good place to start. You can book one through the link below, and we can take it from there.
Disclaimer: This article is educational and informational only. It does not constitute medical advice. Please consult with a healthcare professional before starting any new supplement or making significant dietary changes, particularly if you have existing health conditions or take medications.
