Dr Jane Gilbert

How to Prevent Constipation and Keep Your Gut Healthy on a Low-Carb Diet

From keto to paleo to Dukan, low-carb diets are all the rage—especially at this time of year. They promise weight loss, improved energy, and stable blood sugar levels. However, one common side effect when cutting carbs is constipation. So, how do you maintain a healthy gut and smooth digestion while sticking to a low-carb lifestyle?

I’ve followed a low-carb way of eating for over ten years. It’s kept my weight stable and helped me avoid bingeing on sugary treats (seriously, sugar is like crack cocaine to me!). However, if you’re not careful, cutting carbs can leave you bloated and, well, bunged up. Based on my personal experience and medical research, here are some practical tips for avoiding constipation and keeping your gut happy.

Why Does a Low-Carb Diet Cause Constipation?

When you change your diet, especially by cutting carbs, it can impact your hydration levels and fibre intake, both of which are key for regular bowel movements.

Fibre Matters

When you reduce carbs, you often eliminate high-fibre foods like whole grains, fruits, and some vegetables. Fibre is essential for digestive health—it adds bulk to your stool and nourishes beneficial gut bacteria. Without enough fibre, your digestive system can become sluggish. 

Learn more about the importance of fibre in your diet from Harvard Health.

Water Works

Low-carb diets can lead to rapid water loss, especially in the early stages. As your body burns stored carbs (glycogen) for energy, it releases the water attached to glycogen molecules. This frequent urination can leave you dehydrated, which worsens constipation.

How to Stay Regular on a Low-Carb Diet

The good news? You don’t have to put up with bloating and constipation! Follow these tips to keep things moving smoothly:

1. Stay Hydrated

Drink plenty of water—aim for at least eight glasses a day. Consider adding electrolyte-rich drinks, especially if you’re exercising or sweating a lot. Proper hydration can make a world of difference.

2. Reduce Carbs Gradually

Transition into your low-carb lifestyle slowly to give your body time to adjust and avoid digestive issues.

3. Eat Low-Carb, High-Fibre Foods

Low carb doesn’t mean no carb—prioritize foods that are rich in fibre but low in carbohydrates. Here are some gut-friendly, low-carb options:

• Leafy greens like spinach, kale, and salad leaves

• Avocados

• Chia seeds

• Flaxseeds (I make a low-carb bread using milled flax, egg, grated cheese, and baking powder—it’s full of fibre, satisfying, and delicious!)

• Berries like raspberries and strawberries

• Nuts (almonds, walnuts, macadamia nuts)

4. Include Healthy Fats

Incorporate fats like olive oil, avocado, and coconut oil into your meals—they can help keep digestion moving.

5. Stay Active

Exercise is great for your muscles and your digestive system. Regular physical activity can help prevent constipation.

6. Watch Your Dairy Intake

While dairy is low in carbs, too much cheese or cream can slow digestion for some people.

7. Feed Your Gut Bacteria

Support your gut microbiome by adding fermented foods like yoghurt, kefir, sauerkraut, and kimchi. Prebiotic foods like leeks, garlic, and onions can also help nourish beneficial bacteria in your gut.

8. Try a Fibre Supplement

If you’re struggling to get enough fibre through food, consider a low-sugar, high-fibre supplement like psyllium husk. I use Nixi, a daily fibre shot with 2.9g of fibre, probiotics, and prebiotics—all with just 0.4g of sugar (3.2g carbs). A single dose keeps me regular while staying keto-friendly.

A Low-Carb Diet Doesn’t Have to Mean Digestive Troubles

By staying hydrated, incorporating high-fibre foods, and nourishing your gut bacteria, you can enjoy the benefits of a low-carb lifestyle without the discomfort of constipation. Take care of your gut, and it will thank you!

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