Are Walnuts Low FODMAP?

Are Walnuts Low FODMAP?

Yes, walnuts are low FODMAP! At a serving of 15 nut halves (30g), walnuts contain no detectable FODMAPs and are safe for people following a low FODMAP diet. This makes them one of the more generous nut servings available, perfect for snacking, baking, and adding to meals.

Safe Serving Size

According to Monash University, raw shelled walnuts are safe at 15 halves (30g). At moderate servings just above 30g, fructan levels begin to increase, and at 18 nuts (36g), they reach high FODMAP levels. The good news is that the low FODMAP serving of 15 halves is quite generous.

Why Are Walnuts Safe on Low FODMAP?

Walnuts contain minimal fructans at the recommended serving size:

• Low oligosaccharide content - Walnuts naturally have fewer fructans than many other nuts
• High oil content - The high fat content dilutes potential FODMAPs
• Well-tolerated - Most people with IBS can eat walnuts without symptoms
• Generous serving - 30g is larger than many other nut servings

At 15 walnut halves, fructan levels are below the threshold that triggers IBS symptoms. However, as you increase beyond 30g, fructans accumulate and can cause digestive issues like bloating, gas, and cramping.

Tips for Eating Walnuts on Low FODMAP

• Measure by weight - Use a kitchen scale to ensure you’re at 30g (about 15 halves)
• Count the halves - If you don’t have a scale, count out 15 walnut halves
• Pre-portion snacks - Divide walnuts into 30g portions for convenient snacking
• Choose raw or roasted - Both are low FODMAP; avoid candied or honey-coated versions
• Watch other FODMAPs - Don’t combine with multiple other moderate FODMAP foods
• Store properly - Keep in the refrigerator or freezer to prevent rancidity

Walnut Products and FODMAP Content

Different walnut products have varying considerations:

Walnut oil is a pure fat and contains no FODMAPs, making it an excellent cooking oil for low FODMAP diets. It adds a nutty flavor to salads and roasted vegetables.

Walnuts vs. Other Nuts

Walnuts are one of the most generous low FODMAP nuts:

Walnuts, along with macadamias, pecans, and peanuts, offer some of the most generous low FODMAP servings. This makes them excellent choices for those who enjoy nuts as snacks or in recipes.

Nutritional Benefits of Walnuts

Walnuts are exceptionally nutritious, especially for heart and brain health:

Per 15 halves (30g):

• Omega-3 fatty acids - Highest plant source of ALA (alpha-linolenic acid)
• Protein - About 4-5g
• Fiber - About 2g
• Antioxidants - High in polyphenols
• Vitamin E - Important antioxidant
• Magnesium - Supports muscle and nerve function
• Folate - Important for cell function

Heart Health: Walnuts are particularly beneficial for cardiovascular health due to their high omega-3 content and anti-inflammatory properties.

Brain Health: The omega-3s and antioxidants in walnuts support cognitive function and may help protect against age-related decline.

Low FODMAP Ways to Enjoy Walnuts

Snacks

• Simple snack - Eat 15 walnut halves on their own
• Trail mix - Combine with low FODMAP dark chocolate and pumpkin seeds
• Nut and fruit - Pair with strawberries or a small orange
• Spiced walnuts - Roast with cinnamon and a touch of maple syrup

Breakfast

• Oatmeal topping - Sprinkle chopped walnuts on low FODMAP oats
• Yogurt parfait - Layer with lactose-free yogurt and berries
• Smoothie bowl - Top with crushed walnuts for texture
• Pancakes - Add chopped walnuts to gluten-free pancake batter

Salads

• Green salad - Toast walnuts and add to mixed greens with vinaigrette
• Grain bowl - Sprinkle on quinoa bowls with roasted vegetables
• Spinach salad - Classic combination with strawberries and balsamic
• Arugula salad - Pair with parmesan and lemon dressing

Main Dishes

• Walnut-crusted fish - Coat salmon or white fish with crushed walnuts
• Pesto - Make low FODMAP pesto with walnuts instead of pine nuts
• Pasta - Toss with gluten-free pasta, spinach, and walnut pieces
• Stir-fries - Add toasted walnuts to Asian-inspired dishes

Baking

• Banana bread - Add to low FODMAP banana bread (firm, unripe bananas)
• Muffins - Mix into gluten-free blueberry muffins
• Cookies - Make low FODMAP walnut chocolate chip cookies
• Energy balls - Blend with dates (limit dates), oats, and dark chocolate

Walnut Butter

Walnut butter is similar to other nut butters and can be used in low FODMAP diets:

• Serving size - About 2 tablespoons should be safe (similar to peanut butter)
• Read labels - Avoid versions with honey or high FODMAP sweeteners
• Make your own - Blend 30g walnuts with a touch of salt in a food processor
• Uses - Spread on toast, add to smoothies, or drizzle on oatmeal

Walnut Oil for Cooking

Walnut oil is a low FODMAP cooking oil with a distinctive nutty flavor:

• No FODMAPs - Pure oils contain no carbohydrates or FODMAPs
• Use unrefined - Better for drizzling over finished dishes
• Not for high heat - Walnut oil has a low smoke point
• Storage - Keep refrigerated to prevent rancidity
• Uses - Salad dressings, finishing oil for vegetables, baking

Candied and Flavored Walnuts

Be cautious with flavored walnut products:

Safe:

• Plain roasted walnuts
• Walnuts roasted with salt
• Walnuts with cinnamon (check amount)

Avoid:

• Honey-roasted walnuts (honey is high FODMAP)
• Candied walnuts with high FODMAP sweeteners
• Walnuts with garlic or onion powder
• Walnuts coated in milk chocolate (lactose)

Growing and Storing Walnuts

Buying:

• Choose fresh walnuts with no rancid smell
• Buy from stores with good turnover
• Consider buying in the shell for longer freshness

Storage:

• Refrigerator - Store shelled walnuts up to 3 months
• Freezer - Keep for up to 1 year frozen
• Airtight container - Prevents oxidation and rancidity
• Away from strong odors - Walnuts absorb odors easily

Reintroduction Phase

Walnuts are already low FODMAP at a generous serving, but you can test larger amounts:

1. Start with 15 halves - Confirm tolerance at the low FODMAP serving
2. Wait 3 days - Monitor for any symptoms
3. Try 18-20 halves - Test a moderate serving
4. Wait 3 days - Assess your response
5. Try 25 halves - This tests your upper limit
6. Identify your threshold - Note where symptoms begin

Many people can tolerate larger servings than 15 halves, but it’s important to test individually.

Walnuts for Special Diets

Walnuts fit well into multiple dietary patterns:

• Low FODMAP - 15 halves (30g) is safe
• Gluten-free - Naturally gluten-free
• Dairy-free - No dairy content
• Vegan - Plant-based protein and omega-3s
• Paleo - Acceptable on paleo diets
• Keto - Low carb, high fat
• Heart-healthy - Excellent for cardiovascular health

The Bottom Line

Walnuts are low FODMAP at a generous serving of 15 nut halves (30g), making them one of the best nut choices for people with IBS. They contain minimal fructans at this serving size and provide exceptional nutrition, particularly omega-3 fatty acids for heart and brain health. Walnuts are versatile - enjoy them as snacks, in salads, as a coating for fish or chicken, or baked into low FODMAP treats. Walnut oil is also FODMAP-free and adds wonderful flavor to dressings and finished dishes. Compared to more restrictive nuts like cashews (2-3 nuts) or almonds (18 nuts/22g), walnuts offer more volume and satisfaction.