Understanding the Difference: Low-FODMAP Diet vs. High-FODMAP Eating

FODMAPs are a group of short-chain carbohydrates (sugars) that aren’t properly absorbed in the gut and trigger symptoms in people with IBS. A low-FODMAP diet minimizes these symptoms with alternative foods.

Let’s see how a low vs. high-FODMAP diet impacts the gut, how they differ in their food options, and when it’s actually okay to enjoy (high) FODMAPs.

How the Low-FODMAP Diet Works

According to a narrative review on PubMed, FODMAP stands for all foods that contain fermentable oligosaccharides (soluble plant fibers/prebiotics), disaccharides (lactose/sugar in dairy), monosaccharides (fructose/sugar in fruits), and polyols (sugar alcohols, used as artificial sweeteners and found in some fruits).

They are poorly absorbed in the small intestine and cause bloating, gas, cramping, diarrhea, and constipation. A low-FODMAP diet reduces these symptoms by:

• Easing bloating and pressure: These carbohydrates ferment quickly and produce gas. Reducing them means less gas buildup and bloating.
• Reducing the water in the intestines: FODMAPs draw water into the gut. Limiting them helps prevent intestinal swelling and diarrhea.
• Preventing gut stretches: Less gas and water inside the gut means less stretching in the intestinal wall, which reduces pain, gas, and irregular bowel habits.
• Making bowel habits more stable. This diet also improves stool consistency and frequency, whether the main issue is diarrhea, constipation, or both.

High-FODMAP Eating: What Happens in the Gut?

High-FODMAPs aren’t fully digested in the small intestine. As a result, they increase fermentation in the colon and produce gases like hydrogen and methane; they raise osmotic activity in the gut, meaning that they pull extra water into the intestinal lumen and expand it; and amplify symptoms in people with IBS.

It’s important to note that these foods aren’t unhealthy or harmful. Many high-FODMAPs are nutritious and well-tolerated. However, they do cause symptoms in sensitive individuals due to differences in digestion, gut sensitivity, and motility.

Low-FODMAP vs High-FODMAP: Food Comparison Table

Let’s take a look at low vs. high-FODMAP diet food across different categories. Then, we’ll explain how to use them as a symptom-management tool, not judging food quality.

Important notes:

• Serving size is everything when it comes to high-FODMAP diets and foods; something may be low-FODMAP at one serving size but high-FODMAP at a larger one (like almonds, for instance). Plus, FODMAP tolerance is dose-dependent.
• Low-FODMAP doesn’t equal eating with no limit. They can still cause symptoms if over-consumed. Combining several moderate-FODMAPs in one meal can also stack FODMAP load and aggravate symptoms.
• Watch for hidden high-FODMAP ingredients (typically) in sauces, dressings, marinades, sugar-free products, protein bars, flavored yogurts, processed meats, garlic/onion powders, and wheat-based thickeners.
• Studies use low-FODMAP diets short-term, followed by planned reintroduction to identify triggers. Long-term restriction of high-FODMAPs isn’t recommended at all, as it can affect microbiome diversity.

When Is a High-FODMAP Food Actually Okay?

High-FODMAP foods are okay when the portion is below your personal tolerance level, like a slice of bread, a quarter of an apple, or garlic-infused oil. Tolerance also depends on timing and food combinations. When you avoid stacking high-FODMAP foods in the same meal, symptoms are less likely.

Finally, you can enjoy high-FODMAP foods after the reintroduction phase, once your specific triggers and limits are identified.

Final Thoughts

Learning about low- and high-FODMAPs allows you to know which foods (and in what amounts) work for your body to improve digestive comfort. For a tailored approach, consider using tools like UP-Diet that create personalized low-FODMAP eating plans to match your unique triggers and tolerance levels.