Hitting your protein goal but feeling heavy, bloated and only going every two or three days? Yes, you can put fibre in protein shakes, and it’s one of the simplest ways to close the fibre gap on high-protein days. Pick a soluble fibre that doesn’t turn into gel, start with one 5 g sachet a day, stir it in and drink more water. ADVAGEN Prebio does exactly that without changing how your shake tastes.

The shakes go down easily and the chicken is meal-prepped for the week, so it’s hard to see what’s wrong. Protein isn’t the villain. What’s usually missing is fibre, and your shaker is the easiest place to put it back.

Key takeaways

• Fibre only comes from plants, so meat, eggs and a whey shake bring protein but no fibre.
• The average Singaporean eats about 13 g of fibre a day, well short of the 20 g (women) and 26 g (men) HealthHub recommends.
• Low fibre and low fluid are two common causes of constipation.
• One sachet of ADVAGEN Prebio gives you 5 g of fibre, mixes into the drink of your choice and doesn’t form a gel.
• Build up slowly over 2 to 3 weeks, and drink more water as you go.

Why high-protein days leave you short on fibre

HealthHub explains that dietary fibre comes from plants. Chicken breast, eggs, fish and a scoop of whey are great for protein, but none of them is a plant. When protein takes over most of your plate and your shaker, fibre quietly gets squeezed out.

Most of us start behind, too. SingHealth says the average Singaporean eats 13 g of dietary fibre a day. HealthHub’s national target is 20 g for women and 26 g for men. That’s a gap of 7 to 13 g a day before you’ve even switched to a protein-first plan.

So can too much protein cause constipation? The official pages don’t blame protein itself. HealthHub lists not enough fibre and not enough water or fluids among the causes, and feeling bloated among the symptoms. A high-protein week with little veg and not much water ticks both boxes. Our article on why high-protein diets can cause constipation goes deeper into the gut side, and how often you should poop helps you check what’s normal for you.

Why the usual fibre fixes don’t suit a shake

The first answer is always more fibre from food: vegetables, fruit, beans and wholegrains. It’s the right answer, but it’s hard to keep up at every meal when your eating plan is built around protein.

Fibre powders help, but not all of them suit a shake:

• Some fibres turn to gel. HealthHub describes how soluble fibre can absorb water and turn into a gel-like substance that swells. Leave that kind of fibre in your shaker for a few minutes and you’ll be drinking sludge.
• Bulk-forming products need lots of fluid. The NHS says bulk-forming laxatives need plenty of fluids alongside them.
• Going too fast brings gas. HealthHub warns that too much fibre too quickly can cause gas, bloating or even constipation, which is the very thing you’re trying to fix.

Nothing wrong with any of them. They just don’t fit easily into a morning shake. Our guide to psyllium vs inulin vs resistant dextrin compares the main types side by side.

The easy fix: ADVAGEN Prebio in your protein shake

To be upfront: ADVAGEN Prebio is our own product, and a protein shake is exactly where it’s handy. It’s resistant dextrin, a plant-based soluble prebiotic fibre sourced from corn. According to its product page, it:

• is soluble and doesn’t form a gel
• dissolves and mixes easily in an instant
• doesn’t affect the taste or texture of food and drinks
• goes into the food or drink of your choice

Each sachet gives you 5 g of dietary fibre, and a box holds 30. It’s made to promote bowel regularity and the growth of good gut bacteria. So your chocolate whey still tastes like chocolate whey and pours the way it did yesterday. ADVAGEN’s own article on high-protein eating describes Prebio as something you can easily mix into your daily meals, smoothies or drinks.

Put fibre in your shake, not on your to-do list

ADVAGEN Prebio: 5 g of soluble prebiotic fibre per sachet, 30 sachets a box. No gel, no change to taste or texture. SGD 29.60 a box in the official shop when we checked on 3 November 2026, which works out to about 99 cents a shake.

• Get ADVAGEN Prebio in the official shop
• Ask us on WhatsApp if you have a question first

A daily routine: adding fibre to your protein shake

1. Start with one sachet a day. The label allows 1 to 4 sachets a day for adults. One sachet is 5 g, a quarter of a woman’s 20 g daily target. SingHealth notes that a sudden jump in fibre can leave you bloated, and that raising it slowly over 2 to 3 weeks keeps this down. Add a second sachet only once the first sits well.
2. Stir it in properly. ADVAGEN’s directions are simple: add the sachet to your drink and stir well until it’s dissolved. A few shakes of the bottle does it.
3. Use the drink you already have. The label just says “beverage of choice”, so there’s no special drink to buy. If your protein goes into your morning coffee, our guide to fibre supplement in coffee covers your kopi.
4. Whey or plant, it doesn’t matter. The directions don’t tie Prebio to one kind of drink, so it goes into either. Check the nutrition panel on your tub. If it lists dietary fibre, count it towards your day. If it lists none, the sachet is doing all the fibre work in that glass.
5. Drink more water through the day. HealthHub suggests six to eight cups of fluid or more each day, and warns that adding fibre without extra water can make constipation worse.
6. Keep some fibre on your plate. The sachet is a top-up. A side of vegetables or a piece of fruit with your protein meals still counts.

What a day can look like: your post-gym whey shake with one sachet stirred in and a big glass of water beside it, vegetables with your lunch, a piece of fruit in the afternoon and your water bottle refilled through the office day. Keep that up for two or three weeks. If your tummy is happy, try a second sachet in another drink.

Follow the label. If you’re pregnant, take regular medicines or have a health condition, check with your doctor or pharmacist first. For children, the label says half to one sachet a day, and for children under 6, ask your paediatrician.

When a shake fix isn’t enough

Prebio is a daily fibre top-up. If you’re properly constipated right now and changes to your food and drinks aren’t helping, the NHS says to speak to a pharmacist. HealthHub lists ispaghula husk among the options a pharmacist can give you, and the NHS suggests trying a bulk-forming laxative first when you buy without a prescription. Read more in what fibre is good for constipation.

See a doctor if your constipation doesn’t get better in a week or gets worse, or if you have any of these (HealthHub, NHS):

• blood in your stools, or black or sticky stools
• a sudden change in bowel habits, especially with an unexplained drop in body weight
• very bad stomach pain or cramping
• bloating that keeps coming back (see why you feel bloated)

“Isn’t this just marketing?”

Fair question, and here’s our straight answer. Prebio is a dietary fibre supplement, not a medicine. Everything we’ve said about it comes from its own label and product page: 5 g of fibre, soluble, no gel, no change to taste or texture. We won’t promise you’ll be regular by Friday, and you won’t find made-up reviews here.

Here’s what we will say: if you want a daily, taste-free fibre top-up that fits into a protein shake, this is the one to try. Food still comes first, and if you’re comparing products, our checklist on how to choose a fibre supplement helps you read any label.

Make tomorrow’s shake the fibre one

Click through to the official ADVAGEN shop and you’ll see the current price, the full label and the directions, then check out with ADVAGEN directly. Prefer to ask first? The WhatsApp button opens a chat with ADVAGEN with your question already typed in. Hit send and we’ll get back to you.

• Get ADVAGEN Prebio in the official shop
• Ask us on WhatsApp

FAQ

Does prebiotic fibre in protein shakes help digestion?

It gives you fibre that your protein doesn’t. HealthHub links too little fibre and too little fluid with constipation, so topping up fibre and drinking more water is a sensible step on high-protein days. ADVAGEN Prebio gives you 5 g of fibre per sachet and is made to promote bowel regularity, without changing how your shake tastes. If you’re constipated for more than a week, or things get worse, see a doctor.

Does a high protein diet cause constipation?

The official pages don’t point at protein itself. HealthHub lists not enough fibre and not enough fluids among the common causes. The catch is that protein foods like meat, eggs and whey have no plant fibre, so a protein-heavy day can leave you short on fibre without you noticing. Add fibre, drink more water and keep moving.

Will adding fibre make my protein shake thick?

It depends on the fibre. HealthHub explains that some soluble fibres absorb water and turn into a gel, and that kind can thicken a shake as it sits. ADVAGEN Prebio is soluble but doesn’t form a gel, and its product page says it doesn’t affect the taste or texture of food and drinks. Stir until it’s dissolved and your shake stays the way you like it.

How soon will I notice a difference?

It varies from person to person, so give it time. On food and lifestyle changes for constipation, the NHS says some people see a change in a few days, while for others it can take a few weeks. Build your fibre up over 2 to 3 weeks, keep drinking water and see how your days feel. If you’re no better after a week of constipation, or it gets worse, see a doctor.

What time of day should I have my fibre shake?

Whenever you already drink your shake. ADVAGEN’s directions don’t set a time of day, they just say to stir the sachet into your drink until it dissolves. Tying it to a habit you already have, like the shake after training or at breakfast, makes it much easier to remember. If you take regular medicines, ask your pharmacist about timing.

Is ADVAGEN Prebio a laxative or a probiotic?

Neither. It’s a dietary fibre supplement: resistant dextrin, a soluble prebiotic fibre from corn. A probiotic is a different kind of product, and our guide to probiotic or prebiotic supplements explains the difference. If you need a laxative for constipation right now, speak to a pharmacist.

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References

• HealthHub: the essential benefits of dietary fibre
• HealthHub: constipation
• SingHealth: high fibre diet
• NHS: constipation
• NHS: laxatives
• ADVAGEN Prebio: product page and label

This article is general information, not medical advice. ADVAGEN Prebio is a dietary fibre supplement and is not intended to diagnose, treat, cure or prevent any disease. Speak to a doctor or pharmacist about your own health.