How Fibre Can Reduce Side Effects of GLP-1 Medications

25 Feb

GLP-1 medications such as Ozempic, Wegovy and Mounjaro can be highly effective tools for weight management and metabolic health. However, many people experience side effects — particularly nausea, constipation, bloating or changes in bowel habits.

One simple (and often overlooked) nutrition strategy that can help? Fibre.

When introduced gradually and in the right way, fibre can support digestion, improve gut health, and help ease some of the most common GLP-1 side effects.

Why Do GLP-1 Medications Cause Digestive Side Effects?

GLP-1 medications work by:

Slowing gastric emptying (how quickly food leaves the stomach)
Increasing feelings of fullness
Reducing appetite

While this supports weight loss, it can also lead to:

Nausea or reflux
Constipation
Bloating or discomfort

Nutrition plays a key role in managing these effects — and fibre is part of that picture.

How Fibre Helps When Taking GLP-1s

1. Fibre Supports Regular Bowel Movements

Constipation is one of the most common side effects reported with GLP-1 medications. Fibre helps add bulk to stools and supports regular bowel movements, especially when paired with adequate fluids.

Adding fibre gradually can help prevent discomfort and keep digestion moving.

2. Fibre Feeds the Gut (Without Overloading It)

Certain fibres act as prebiotics, feeding beneficial gut bacteria. A healthier gut microbiome may help reduce bloating and improve digestive tolerance over time.

The key is variety and balance, not very large portions all at once.

3. Fibre Helps Stabilise Blood Sugar

Fibre slows digestion and carbohydrate absorption, helping to reduce blood sugar spikes. This can support overall metabolic health and may help reduce nausea triggered by large blood sugar swings.

The Best Fibre Sources to Include on GLP-1s

Gentle, well-tolerated fibre sources tend to work best, especially early on:

Oats and porridge
Berries
Kiwi, pears, apples (with skin)
Lentils and beans (start small)
Chia seeds or ground flaxseed
Vegetables like carrots, courgette, spinach and broccoli

Tip: Spread fibre across meals rather than concentrating it in one sitting.

How to Increase Fibre Without Worsening Symptoms

If you’re taking a GLP-1 medication, how you add fibre matters just as much as how much.

Increase fibre slowly over 1–2 weeks
Drink fluids regularly throughout the day
Chew food well and eat slowly
Pair fibre with protein to improve tolerance
Avoid large, very high-fibre meals when appetite is low
A Final Word
GLP-1 medications can be powerful tools — but they work best when supported with the right nutrition. Fibre isn’t about restriction or rules; it’s about supporting digestion, comfort, and long-term health.
If you’re struggling with side effects or unsure how to structure your meals while taking a GLP-1, working with a dietitian can make a big difference.
Need Support with your diet on a GLP-1?
At Wellth, we offer personalised nutrition support for people prescribed GLP-1 medications — focused on nourishment, tolerance, and sustainable progress.
Book an appointment with a registered dietitian today www.wearewellth.ie