What foods are on a low fermentation diet?

January 7, 2026 •

4 min read

An estimated 70 million Americans suffer from digestive discomfort, often linked to imbalances in gut bacteria. The low fermentation diet is a targeted approach designed to manage these issues by focusing on foods that are easily digested, reducing the fuel available for bacteria in the small intestine.

Quick Summary

This guide details the food options and restrictions of a low fermentation diet, a strategy used to alleviate symptoms of SIBO and other digestive conditions. It explains the importance of food choices and meal timing to minimize gas production and discomfort. The information helps in managing gut health with a less restrictive dietary approach than other protocols.

Key Points

Symptom Management: The low fermentation diet is designed to reduce SIBO and IBS symptoms by limiting fermentable foods.
Meal Spacing: Adherence to a 4-5 hour gap between meals is crucial for allowing the gut's natural cleansing waves to function.
Allowed Foods: The diet permits lean proteins, white starches like rice and potato, low-fiber fruits, and specific vegetables.
Restricted Foods: Key foods to avoid include most legumes, high-fructose fruits, high-fiber whole grains, and lactose-containing dairy.
LFD vs. Low FODMAP: LFD is often less restrictive than the low-FODMAP diet and may be more sustainable for long-term use, especially regarding foods like onion and garlic.
Professional Guidance: It is recommended to consult a healthcare professional or dietitian to personalize the diet and prevent nutritional deficiencies.

The low fermentation diet (LFD), also known as the Cedars-Sinai diet, is an eating plan developed to help manage symptoms associated with Small Intestinal Bacterial Overgrowth (SIBO) and Irritable Bowel Syndrome (IBS). The core principle is to reduce the intake of fermentable carbohydrates and high-fiber foods that are not properly absorbed in the small intestine. When these undigested particles reach the small bowel, they are fermented by bacteria, causing gas and digestive distress.

Key Principles of Low Fermentation Eating

Beyond specific food choices, the LFD incorporates strategic meal timing to maximize the digestive system's natural cleansing process. The migrating motor complex (MMC) is a 'housekeeping wave' that sweeps the small intestine clean between meals. Eating frequently disrupts this process. Therefore, a key component of the LFD is to space meals four to five hours apart with no snacking in between, allowing the MMC to function effectively. This helps prevent the bacterial overgrowth that the diet is designed to address. The diet is generally considered a less restrictive, more sustainable option than a strict low-FODMAP diet for long-term symptom management.

Allowed Foods on a Low Fermentation Diet

Choosing the right foods is critical to minimizing fermentation and its associated symptoms. The following categories represent common food groups that form the foundation of a low fermentation diet.

Proteins

Protein sources are typically well-tolerated and form a staple of the diet. They are not fermentable and are crucial for nutrition and satiety.

Lean meats (chicken, beef, lamb)
Fish and seafood
Eggs
Tofu (firm, in moderation)

Grains and Starches

White rice
Plain white pasta
White bread and flour products
Potatoes and sweet potatoes (in moderation)
Quinoa

Vegetables

Many vegetables are suitable, though it's important to choose those that are less fibrous or gas-producing. Unlike a low-FODMAP diet, garlic and onion can often be tolerated in moderation, but individual tolerance varies significantly.

Carrots
Cucumbers
Eggplant
Lettuce
Leafy greens (cooked spinach)
Mushrooms
Zucchini

Fruits

Most fruits are acceptable, but high-fructose fruits should be limited, especially if they trigger symptoms.

Berries (blueberries, raspberries)
Grapes
Kiwi
Bananas (ripe, in moderation)
Citrus fruits

Fats and Oils

Healthy fats are an essential part of the diet and do not contribute to bacterial fermentation.

Olive oil
Avocado oil
Coconut oil
Butter

Dairy and Alternatives

Lactose-free dairy products
Hard cheeses (aged cheddar, parmesan)
Lactose-free kefir

Foods to Avoid or Limit on a Low Fermentation Diet

To minimize bacterial activity, certain foods are restricted due to their high content of fermentable carbohydrates, fiber, or indigestible sugars.

High-Fructose Foods: Apples, pears, high fructose corn syrup.
Legumes: Beans, lentils, peas.
High-Fiber Grains: Whole grains, bran.
High-Fiber Vegetables: Cruciferous vegetables like broccoli, cauliflower, cabbage, and Brussels sprouts.
Dairy (lactose): Milk, yogurt, ice cream.
Artificial Sweeteners: Sorbitol, mannitol, xylitol, stevia.

Comparison: Low Fermentation vs. Low FODMAP

The Low Fermentation Diet (LFD) and the low-FODMAP diet are both used to manage digestive symptoms, but they differ in several key areas. The LFD, developed by Dr. Mark Pimentel, emphasizes meal spacing and focuses on reducing hard-to-digest carbohydrates, while the low-FODMAP diet restricts specific types of fermentable carbohydrates (FODMAPs). This table highlights the key differences.


Feature	Low Fermentation Diet (LFD)	Low FODMAP Diet
Primary Goal	Reduce fermentable carbs and allow MMC to clear SIBO	Identify and reduce specific FODMAPs triggering IBS symptoms
Meal Timing	Emphasizes 4-5 hour meal spacing with no snacking	No specific meal timing rules
Onion/Garlic	Often tolerated in moderate amounts	Restricted due to high fructan content
Legumes	Excludes all legumes and beans	Allows for small, specific serving sizes of some canned legumes
Cruciferous Veggies	Avoids high-fiber types like broccoli and cauliflower	Allows small portions of some types
Restrictiveness	Generally considered less restrictive and more sustainable long-term	Highly restrictive during elimination phase, requires careful reintroduction

Creating a Meal Plan on a Low Fermentation Diet

Designing a meal plan that adheres to LFD principles can provide relief while ensuring nutritional adequacy. A sample day might look like this:

Breakfast: Scrambled eggs with cooked spinach.
Lunch: Grilled chicken or fish with white rice and steamed carrots.
Dinner: Baked salmon with a side of plain potato and sautéed zucchini.

It is vital to listen to your body and adjust food choices based on your individual tolerance. For example, while many people on LFD can tolerate cooked leafy greens, a person with severe symptoms might need to limit them further. Meal prep can help maintain consistency with meal timing and food choices.

Conclusion

The low fermentation diet offers a structured yet flexible approach to managing symptoms of SIBO and IBS by limiting fermentable carbohydrates and focusing on crucial meal timing. By understanding which foods are on a low fermentation diet and adhering to the guidelines, individuals can experience significant relief from bloating, gas, and discomfort. As with any restrictive dietary plan, it is recommended to work with a healthcare professional or registered dietitian to ensure proper nutritional balance and a tailored strategy for your specific health needs. For more detailed information on Low Fermentation Eating, you can explore resources from the diet's developers at the Cedars-Sinai Medical Center.

Frequently Asked Questions

The main goal is to reduce symptoms like bloating, gas, and abdominal pain caused by Small Intestinal Bacterial Overgrowth (SIBO). It starves the excess bacteria in the small intestine that thrive on fermentable carbohydrates.

The diet recommends spacing meals four to five hours apart with no snacking. This allows the gut's natural cleansing mechanism, the Migrating Motor Complex (MMC), to sweep undigested food and bacteria from the small intestine.

While the name might be misleading, the focus is on reducing fermentation in the small intestine. The diet often excludes dairy products like yogurt due to lactose content, and high-fiber sauerkraut is generally avoided. Lactose-free alternatives may be tolerated.

No, while both reduce fermentable carbohydrates, they are different. The low fermentation diet can be less restrictive, allowing foods like onion and garlic that are typically excluded on a low-FODMAP diet.

Like any restrictive diet, there is a risk of nutritional deficiencies if followed long-term without professional guidance. It's important to work with a dietitian to ensure the diet is balanced and meets your needs.

You should limit or avoid fruits high in fructose, which can be problematic. This includes apples and pears. Low-fructose fruits like berries and bananas in moderation are generally better tolerated.

Some alcohol, particularly spirits, may be tolerated, but caution is advised. Sugary mixers and hoppy beers should be avoided. As always, moderation is key.