How to get 30g of fiber on a low-carb diet?

November 11, 2025 •

4 min read

While the average person already falls short of the recommended daily fiber intake, those on a low-carb diet face an extra challenge due to the restriction of many fiber-rich carbohydrates. This comprehensive guide explains how to get 30g of fiber on a low-carb diet by focusing on smart food choices and effective supplementation.

Quick Summary

This article details practical strategies and lists specific foods to help achieve a 30g daily fiber goal while adhering to low-carb principles. It covers high-fiber, low-carb food options, the roles of soluble and insoluble fiber, and recommendations for appropriate supplements.

Key Points

Focus on Low-Carb, High-Fiber Foods: Prioritize options like chia seeds, avocado, leafy greens, and nuts to meet your 30g fiber goal.
Differentiate Fiber Types: Understand that soluble fiber helps manage blood sugar and cholesterol, while insoluble fiber promotes digestive regularity.
Incorporate Seeds into Your Diet: Seeds like chia and flax are powerhouses of fiber with minimal net carbs, making them a staple for low-carb diets.
Use Supplements Wisely: If needed, fiber supplements like psyllium husk can be effective, but choose those without added sugars and increase intake gradually.
Hydrate to Prevent Issues: Ensure you drink plenty of water, especially when increasing your fiber intake, to help with digestion and prevent constipation.
Add Volume with Vegetables: Bulk up your meals with plenty of low-carb vegetables like broccoli, Brussels sprouts, and spinach to feel full and increase fiber.
Start Slow to Avoid Digestive Discomfort: Introduce high-fiber foods and supplements slowly over time to prevent bloating and gas.

Why Fiber Matters on a Low-Carb Diet

Fiber, an indigestible carbohydrate, is vital for several aspects of health, particularly when following a low-carb or ketogenic diet. Adequate fiber intake on a low-carb plan offers numerous advantages:

Promoting Digestive Health: Fiber can help prevent or relieve constipation, which can be a common issue when starting a low-carb diet.
Aiding Satiety: High-fiber foods contribute to feeling full, which supports weight management efforts.
Balancing Blood Sugar: Soluble fiber helps slow sugar absorption, preventing rapid spikes in blood glucose.
Boosting Gut Health: Fiber ferments in the gut, nourishing beneficial bacteria and contributing to a healthy microbiome.

The Two Types of Fiber: Soluble vs. Insoluble

Both types of fiber are important for different health benefits:

Soluble Fiber: Dissolves in water to form a gel, which helps lower cholesterol and blood sugar. Low-carb sources include chia seeds, flax seeds, and avocado.
Insoluble Fiber: Doesn't dissolve in water and adds bulk to stool, promoting regular bowel movements. Leafy greens, nuts, and cruciferous vegetables are good low-carb sources.

High-Fiber, Low-Carb Foods

To get 30g of fiber on a low-carb diet, focus on specific plant-based foods that are high in fiber and low in net carbs.

Seeds

Seeds are excellent sources of fiber and healthy fats, with minimal net carbs.

Chia Seeds: One ounce (28g) provides nearly 10g of fiber and only 2g of net carbs.
Ground Flaxseed: Two tablespoons contain 4g of fiber with negligible net carbs.
Pumpkin Seeds: An ounce has almost 2g of fiber and just over 1g of net carbs.

Nuts

Nuts offer fiber but vary in carb content, so moderation is key.

Almonds: An ounce (23 kernels) provides about 3.5g of fiber and 2.5g of net carbs.
Pecans: Three-quarters of a cup (100g) contains nearly 10g of fiber and 4g of net carbs.

Low-Carb Vegetables

Many non-starchy vegetables are rich in fiber and other nutrients.

Avocado: Half a large avocado provides 7g of fiber and only 2g of net carbs.
Broccoli: One cup (150g) cooked contains 5g of fiber and 6g of net carbs.
Brussels Sprouts: A cup roasted offers 4g of fiber and 7g of net carbs.
Spinach: A half-cup (100g) cooked provides 4g of fiber and only 1g of net carb.

Berries

Some berries can be included in moderation due to their fiber content and lower net carbs compared to other fruits.

Raspberries: A half-cup offers 4g of fiber and 3.3g of net carbs.

Comparison of Fiber Sources

This table highlights the fiber and net carb content of typical servings of low-carb and high-carb options:


Food Item	Serving Size	Fiber (g)	Net Carbs (g)
Chia Seeds	2 tbsp	10	2
Avocado	½ large	7	2
Cooked Spinach	½ cup	4	1
Raspberries	½ cup	4	3.3
Whole Grain Bread	1 slice	~2	~12
Cooked Brown Rice	½ cup	~2	~20

Sample Low-Carb, High-Fiber Meal Ideas

Incorporating high-fiber, low-carb foods into your daily meals is achievable with planning. A sample day might include:

Breakfast: Chia seed pudding with chia seeds (10g fiber) and raspberries (4g fiber).
Lunch: Salad with avocado (7g fiber) and almonds (3.5g fiber), plus a side of sautéed spinach (4g fiber).
Dinner: Roasted protein with a side of roasted Brussels sprouts (4g fiber) and steamed broccoli (5g fiber).

Fiber Supplements for Low-Carb Diets

Supplements can help if you struggle to meet your fiber goals through food alone. Choose supplements without added sugars.

Psyllium Husk: A popular supplement providing both soluble and insoluble fiber. One tablespoon offers 8g of fiber with minimal net carbs. Mix with plenty of water.
Acacia Fiber: A soluble fiber that can promote digestive health.

Start with a small dose and gradually increase, ensuring adequate water intake to prevent blockages.

Practical Tips for Boosting Your Fiber Intake

Start Gradually: Increase fiber intake slowly to avoid digestive discomfort like bloating and gas.
Stay Hydrated: Drink plenty of fluids, especially with fiber supplements, to aid digestion.
Prioritize Volume: Use high-fiber, low-carb vegetables to add bulk to your meals and enhance satiety.
Keep Seeds Handy: Add chia or flax seeds to various dishes for an easy fiber boost.
Check Labels: Be mindful of hidden sugars in packaged low-carb foods that could affect your diet.

Conclusion

Achieving 30g of daily fiber on a low-carb diet is possible by focusing on fiber-rich, low-carb foods like seeds, nuts, and non-starchy vegetables. Supplements like psyllium husk can also be helpful. Gradually increase fiber intake and drink plenty of water to support digestive health and feel satisfied on your low-carb journey.

Sources

Perfect Keto. "How to Get Enough Fiber on Keto." perfectketo.com, 16 June 2025, perfectketo.com/how-to-get-fiber-on-keto/.
Everyday Health. "The 12 Best Sources of Fiber on the Keto Diet." everydayhealth.com, 9 Nov. 2022, everydayhealth.com/ketogenic-diet/diet/best-sources-fiber-on-keto-diet/.
Diet Doctor. "15 High-fiber Foods that Are Low in Carbs." dietdoctor.com, 3 Oct. 2022, dietdoctor.com/low-carb/high-fiber-foods.
Healthy Food Guide. "Getting enough fibre on a keto diet." healthyfood.com, 1 Nov. 2019, healthyfood.com/ask-the-experts/low-carb-fibre-intake/.
Mayo Clinic. "Dietary fiber: Essential for a healthy diet." mayoclinic.org, mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/fiber/art-20043983.
Harvard T.H. Chan School of Public Health. "Fiber." nutritionsource.hsph.harvard.edu, nutritionsource.hsph.harvard.edu/carbohydrates/fiber/.
The IBS Dietitian. "How To Get 30g of Fibre a Day." theibsdietitian.com, 15 Feb. 2022, theibsdietitian.com/blog/get-30g-fibre-day.
It's Skinny Pasta. "HOW TO GET ENOUGH FIBER ON KETO." itsskinny.com, 1 Dec. 2023, itsskinny.com/blogs/news/how-to-get-enough-fiber-on-keto.

Frequently Asked Questions

Yes, it is possible to achieve a daily intake of 30g of fiber on a low-carb or ketogenic diet. It requires strategic meal planning and focusing on specific high-fiber, low-carb foods such as seeds, nuts, and non-starchy vegetables.

Some of the best low-carb fiber sources include chia seeds, flaxseed, avocado, leafy greens (like spinach and kale), cruciferous vegetables (broccoli, Brussels sprouts), and nuts (almonds, pecans).

Rapidly increasing fiber intake can cause bloating, gas, and cramping. To avoid this, introduce high-fiber foods and supplements slowly over several weeks and increase your fluid intake significantly.

Fiber supplements are not strictly necessary but can be helpful if you struggle to meet your daily 30g goal through food alone. Supplements like psyllium husk are a low-carb option, but always check labels for added sugars.

On a low-carb diet, you focus on 'net carbs,' which are calculated by subtracting the grams of fiber from the total grams of carbohydrates. Since fiber is indigestible, it does not raise blood sugar.

When you increase your fiber intake, it is critical to drink plenty of water. Water helps soluble fiber form a gel and insoluble fiber to add bulk, both of which are essential for proper digestion and preventing constipation.

Add a tablespoon or two of chia or ground flaxseed to smoothies or yogurt. Use low-carb vegetables like spinach and cauliflower to bulk up stir-fries and salads. Avocado is also an easy, fiber-rich addition to many dishes.