Kale can cause gas and bloating mainly due to its high fiber content.
In addition, it does contain significant amounts of certain carbohydrates that are hard to digest that can also cause gas.
In this short post, I’ll walk you through how likely it is that kale causes gas.
Table of Contents
Why Do Some Leafy Greens Like Kale Cause Gas?
First you need to understand what causes bloating and flatulence.
The root of both is carbohydrates.
When a carbohydrate can’t easily be digested in the stomach or small intestine, it is fermented in the large intestine, which produces various gasses. These gasses can be passed through flatulence, or can build up and cause bloating.
There are 2 main classes of carbohydrates that don’t digest well and often cause stomach problems, although there is some overlap between the two:
- Fiber – You probably know that fiber can’t be digested, but it can ferment. Some fiber is good, but too much can cause problems.
- FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) – Fodmaps are a known group of short-chain carbohydrates that we can’t always absorb well. Sensitivity can vary significantly from person to person.
Now we can look at how much of these 2 groups are in kale.
Is Kale High in Fiber?
The table below shows the nutrition data for 100 grams of raw kale from the USDA’s nutrition database.
For reference, 1 cup of loosely packed kale is about 21 grams, so a large kale salad might contain about 5 cups or so.
| Kale | |
|---|---|
| Energy (kcal) | 35 |
| Protein (g) | 2.92 |
| Total Lipid (g) | 1.49 |
| Carbohydrate (g) | 4.42 |
| Fiber (g) | 4.1 |
| Sugars (g) | 0.99 |
A single serving of kale has just over 4 grams of fiber, which is relatively high compared to most other vegetables.
If you ate a large kale salad, you could end up with 20 grams of fiber, plus more from other ingredients. This is a large amount considering that adults should typically aim for at least 20 grams of fiber per day.
Does Kale Contain any FODMAPs?
While it’s hard to get specific data about FODMAPs, one study did look at how much of them are in kale.
The data below is also per 100 grams, and shows that kale does contain a significant amount of 3 FODMAPs.
| Kale | |
|---|---|
| Moisture | 88 g |
| Fructose | 1.10 g |
| Sorbitol | 0.16 g |
| Total FOS | 0.51 g |
At the same time, these levels are not that high, and they likely won’t cause stomach issues by themselves, even with multiple servings.
Kale is not considered a high fructose food. It generally takes over 15 grams before even people sensitive to fructose have any issues.
Similarly, it typically takes at least 5 grams of sorbitol to cause issues.
The last one is slightly more concerning, as just 4 grams of fructooligosaccharides (FOS) can stimulate bowel movements. But that would be an awfully large serving of kale.
Can You Be Allergic to Kale?
It is not common, but some people do develop an allergy to kale.
This typically comes with an allergy to the rest of the cruciferous vegetable family as well, which includes foods like broccoli, cauliflower, cabbage, and brussels sprouts.
However, I want to be very clear that this is not common, and a kale allergy usually comes with other symptoms like itchy skin or swelling, and not just excess gas.
Is Kale the Only Thing Giving You Gas?
Unless you’re eating plain kale chips, it’s very likely that some other food is contributing to some portion of your gas.
If you notice that you only seem to get bloated after eating certain recipes with kale, then you’re probably having issues because of other ingredients.
