Spinach is a low FODMAP food. It appears on low FODMAP vegetable lists from major research institutions, and it’s low in the specific sugars (fructose, fructans, and polyols) that trigger digestive symptoms in people with IBS. A standard serving of raw baby spinach leaves is safe during the elimination phase of a low FODMAP diet.
What Makes Spinach Low FODMAP
Spinach is naturally low in the fermentable carbohydrates that define the FODMAP group: oligosaccharides (fructans and galactans), disaccharides (lactose), monosaccharides (excess fructose), and polyols (sugar alcohols). Peer-reviewed research published in Current Gastroenterology Reports categorizes spinach as both a low FODMAP vegetable and a low fructose alternative, meaning it doesn’t contain the excess free fructose that causes trouble for many people with fructose malabsorption.
This matters because fructose and fructans are two of the most common FODMAP triggers. Studies show that higher doses of fructans and fructose are associated with more severe gut symptoms, so vegetables that are naturally low in both give you a wider margin of safety at the table.
Serving Size Still Matters
Even low FODMAP foods can become moderate or high FODMAP if you eat enough of them. With spinach, a handful of baby spinach leaves (roughly one cup of loosely packed raw leaves) is the commonly referenced safe portion. Monash University, the research group behind the FODMAP diet, suggests blending a handful of baby spinach into a smoothie as a go-to low FODMAP option.
If you’re eating spinach as a cooked side dish, keep in mind that spinach shrinks dramatically when heated. A large bowl of raw leaves cooks down to a few tablespoons, so it’s easy to consume a much larger volume of actual spinach in cooked form than you realize. Weigh or measure your raw leaves before cooking if you want to stay within a tested low FODMAP portion during the elimination phase.
Raw vs. Cooked Spinach
There’s no published evidence that cooking spinach changes its FODMAP classification. However, cooking does concentrate the plant material per cup. One cup of raw spinach is about 30 grams, while one cup of cooked spinach can be 180 grams or more, representing roughly six times the amount of actual leaf. That concentration effect is the main risk. A cup of raw spinach in a salad is a very different quantity than a cup of cooked spinach on your plate.
If you enjoy cooked spinach, start with a smaller portion (a few tablespoons of the cooked product) and note how you feel. During the reintroduction phase, you can gradually increase your serving to find your personal tolerance level.
Baby Spinach vs. Mature Spinach
Baby spinach and mature (sometimes called English) spinach come from the same plant, harvested at different stages. Baby spinach leaves are picked earlier, and they tend to be milder and more tender. Both types are considered low FODMAP at standard servings. Baby spinach is the variety most frequently referenced in FODMAP guidance, likely because it’s the most widely available in pre-washed bags and is commonly eaten raw in salads and smoothies.
If you prefer mature spinach for cooking, the same serving size principles apply. Measure before you cook, and treat it the same as baby spinach in terms of portion awareness.
Recent Updates to FODMAP Ratings
In July 2024, Monash University completed a full review of the vegetable category in their FODMAP Diet app. This update added missing portion guidance and revised how fructose-containing vegetables are rated, using updated cutoff values. Some vegetables had their traffic light ratings change as a result. Because spinach was already established as low in fructose and other FODMAPs, it remains in the safe category. If you use the Monash app, it’s worth checking for the latest serving size details, as the update filled in gaps that previously existed for some foods.
Other Low FODMAP Leafy Greens
If you eat a lot of leafy greens and want variety beyond spinach, several options are also low FODMAP at typical serving sizes:
- Arugula (rocket): Peppery flavor, works well in salads and on pizza.
- Red and green leaf lettuce: Mild and versatile as a salad base.
- Romaine lettuce: A good source of folate. Two cups of romaine provides roughly the same folate as half a cup of spinach.
- Iceberg lettuce: Lower in nutrients than darker greens but reliably low FODMAP even in larger portions.
Mustard greens and bok choy are additional options, though you should verify current portion sizes in the Monash app since these can vary. Mixing different greens into your rotation helps you get a broader range of vitamins and minerals while keeping your total FODMAP load from any single vegetable in check.
Using Spinach During Each Diet Phase
During the elimination phase, stick to a single handful (about one cup raw) of spinach per meal. This keeps you well within tested low FODMAP limits and avoids any stacking effect if you’re also eating other FODMAP-containing foods in the same sitting.
During reintroduction, spinach isn’t typically used as a challenge food because it doesn’t contain meaningful amounts of any single FODMAP category. Instead, it serves as a reliable “safe” vegetable you can build meals around while you test higher FODMAP foods one at a time.
In the personalization phase, most people find they can eat spinach freely without symptoms. If you’ve identified that you’re sensitive to fructans or fructose specifically, you may still want to be mindful of very large cooked portions, but for the majority of people following a low FODMAP diet, spinach is one of the easiest vegetables to keep on your plate.