What are FODMAPs and why do they matter?
FODMAPs are a collection of short-chain carbohydrates that can be poorly absorbed in the small intestine, leading to digestive issues in sensitive individuals, particularly those with Irritable Bowel Syndrome (IBS). The acronym stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. When these carbohydrates reach the large intestine, gut bacteria ferment them, which produces gas and attracts water into the bowels. For people with a sensitive gut, this process can cause pain, bloating, gas, and changes in bowel habits. The low FODMAP diet, developed by researchers at Monash University, is designed to help manage these symptoms by temporarily restricting foods high in these compounds.
The FODMAP content of spring onions
Many people on a low FODMAP diet miss the flavor of onion and garlic, both of which are high in fructans, a type of oligosaccharide. This is where spring onions, also known as green onions or scallions, become an incredibly useful substitute. The key lies in understanding that not all parts of the plant have the same FODMAP level. Extensive lab testing by Monash University confirms this distinction.
The white bulb and pale green stem are high in fructans, the same compound that makes regular onions problematic for many with IBS. Consuming this part is generally not recommended during the elimination phase of the diet. However, recent retesting by FODMAP Friendly has suggested that a small serving of the white bulb (19g) may be low FODMAP, though it's often safer to stick to the greens during the elimination phase.
The green, leafy tops are considered low in FODMAPs and can be enjoyed in moderate amounts, providing a mild onion flavor without triggering symptoms. This is a game-changer for those seeking to add flavor back into their meals. In fact, you can use quite a generous amount—up to 1.5 cups (75g) of chopped green tops is considered a safe serving during the elimination phase of the diet, according to Monash University.
Using spring onions on a low FODMAP diet
To effectively incorporate spring onions while managing IBS symptoms, follow these simple preparation steps:
- Snip the tops: Cut the green tops from the white bulb, discarding the high FODMAP bulb and pale green section.
- Wash thoroughly: Clean the green stalks under running water to remove any dirt.
- Chop and store: Chop the green leaves and use immediately as a garnish or add them during cooking. You can also freeze chopped greens in an airtight bag for up to three months.
- Infuse with oil: Fructans are water-soluble but not oil-soluble. You can sauté the white bulb in oil to infuse the flavor, then remove the bulb pieces before adding other ingredients.
This method allows you to capture the essence of onion without the problematic fructans leaching into your dish. Using the green tops is a straightforward way to add a fresh, mild onion taste to a variety of recipes.
Comparison of onion types on a low FODMAP diet
To better understand your options, here's a comparison of common onion and onion-like vegetables and their FODMAP suitability during the elimination phase of the diet.
| Vegetable Type | Low FODMAP Part | High FODMAP Part | Safe Serving Size | Notes |
|---|---|---|---|---|
| Spring Onion | Green tops | White bulb | 75g (1.5 cups) of green tops | Green tops offer mild onion flavor. |
| Regular Onion (red, white) | None | Entire onion | None | High in fructans and should be avoided. |
| Chives | Entire plant | None | Generous serving | A great, safe alternative for onion flavor. |
| Leeks | Green leaves | White bulb | ⅔ cup of green leaves | Similar to spring onions, use the green part only. |
| Garlic | None | Entire bulb | None | High in fructans, use garlic-infused oil instead. |
Maximizing flavor with low FODMAP substitutes
Avoiding high FODMAP onions doesn't mean sacrificing flavor. In addition to the green tops of spring onions and leeks, other alternatives can help you build complex and satisfying tastes in your cooking.
- Garlic-infused oil: A crucial low FODMAP hack. Because fructans are not oil-soluble, you can purchase or make your own garlic-infused oil to add that signature aroma without the digestive distress.
- Asafoetida powder (hing): This spice offers a powerful, pungent flavor reminiscent of onion and garlic. A small pinch goes a long way and can be used in cooked dishes.
- Herbs and spices: Experiment with a wide range of low FODMAP herbs and spices to build depth of flavor, such as basil, oregano, cumin, turmeric, and smoked paprika.
Conclusion
So, is spring onion high in FODMAP? The answer is yes and no, depending on the part of the plant you use. The white bulb is high in fructans and best avoided during the elimination phase of the low FODMAP diet. However, the green tops are a fantastic low FODMAP alternative, allowing you to add a delicate onion flavor to your meals without causing digestive issues. By understanding this distinction and using simple preparation techniques, you can effectively manage IBS symptoms while continuing to enjoy flavorful, nutritious food. For the most up-to-date and specific serving size information, the Monash University FODMAP Diet App is the gold standard resource.
How to get more mileage from your spring onions
For a constant supply of low FODMAP green onion flavor and to reduce food waste, try regrowing the green tops from the leftover white bulbs.
Instructions:
- Cut off the green tops, leaving about an inch of the white bulb with the roots attached.
- Place the bulbs root-side down in a small glass or jar with an inch or two of water.
- Set the glass on a sunny windowsill.
- Change the water every couple of days to prevent cloudiness.
- New green shoots will emerge within a week or two. Snip the new greens as needed for cooking.
This provides a sustainable and convenient way to always have low FODMAP onion flavor at your fingertips.
