In this article
- What counts as a cruciferous vegetable
- Cruciferous vegetables fiber, ranked by the cooked cup
- Broccoli, cauliflower, cabbage and Brussels sprouts up close
- How crucifers stack up against other vegetables
- The raw crucifers: salads, slaws and garnishes
- Myth vs fact: does cooking destroy the fiber?
- Easy ways to eat more crucifers
- Going easy on your gut
- What research is still asking
- Cruciferous vegetables and fiber: common questions
- Sources
You roast a sheet pan of Brussels sprouts for dinner and eat a cup without thinking much about it. That cup just delivered 6.4 grams of fiber, roughly a quarter of a woman’s daily target, for 65 calories.
Brussels sprouts sit at the top of the cruciferous vegetables fiber rankings, but the whole family is strong. Broccoli, cauliflower, kale and collards all land between 4.7 and 5.2 grams per cooked cup.
Below you’ll find every common crucifer ranked by the cup and by the calorie, what changes between raw and cooked, and a few easy ways to work more of them into your week.
What counts as a cruciferous vegetable
Cruciferous vegetables belong to the cabbage family, called Brassicaceae. The National Cancer Institute lists arugula, bok choy, broccoli, Brussels sprouts, cabbage, cauliflower, collard greens, horseradish, kale, radishes, rutabaga, turnips, watercress and wasabi among them.
What ties the group together is a set of sulfur compounds called glucosinolates. They give these vegetables their sharp smell and slightly bitter taste, and they break down into other compounds as you chop, chew and digest them.
That makes the family surprisingly diverse on the plate. It includes leafy greens, flower heads, roots and spicy condiments, and their fiber numbers vary just as much.
Horseradish and wasabi are part of the family too, but you eat them by the teaspoon. They bring heat and flavor rather than meaningful fiber, so this guide focuses on the crucifers you eat by the cup.
Cruciferous vegetables fiber, ranked by the cooked cup
These numbers come from the Dietary Guidelines food sources table. Each line is one cup cooked, with fiber per 100 calories so you can compare efficiency too.
| Vegetable (1 cup cooked) | Fiber | Calories | Fiber per 100 calories |
|---|---|---|---|
| Brussels sprouts | 6.4 g | 65 | 9.8 g |
| Broccoli | 5.2 g | 54 | 9.6 g |
| Turnip greens | 5.0 g | 29 | 17.2 g |
| Cauliflower | 4.9 g | 34 | 14.4 g |
| Collard greens | 4.8 g | 63 | 7.6 g |
| Kale | 4.7 g | 43 | 10.9 g |
| Savoy cabbage | 4.1 g | 35 | 11.7 g |
| Red cabbage | 4.1 g | 41 | 10.0 g |
| Turnip | 3.1 g | 34 | 9.1 g |
| Rutabaga | 3.1 g | 51 | 6.1 g |
| Green cabbage | 2.8 g | 34 | 8.2 g |
| Mustard greens | 2.8 g | 36 | 7.8 g |
Every entry gives at least 6 grams of fiber per 100 calories, which is better than most fruits. Turnip greens and cauliflower are the efficiency champions, with cauliflower delivering nearly 5 grams for just 34 calories.
Cabbage is the one that surprises people. Green cabbage gives 2.8 grams per cooked cup, but savoy and red cabbage reach 4.1, so the variety you buy makes a real difference.
Broccoli, cauliflower, cabbage and Brussels sprouts up close
These four make up most of the cruciferous vegetables people actually buy. Each has its own strengths beyond fiber.
Brussels sprouts
Brussels sprouts lead the family with 6.4 grams per cooked cup. Raw, a cup of whole sprouts weighs about 88 grams and carries 3.3 grams of fiber, plus about 75 milligrams of vitamin C.
Shaved raw Brussels sprouts make a sturdy slaw. Roasting shrinks them, so a cooked cup holds more sprouts and therefore more fiber.
Broccoli
A cup of cooked broccoli gives 5.2 grams, while a cup of raw chopped broccoli, about 91 grams, gives 2.4. The raw cup is lighter because the florets don’t pack together until they soften.
Cauliflower
Cooked cauliflower carries 4.9 grams per cup for only 34 calories. Raw, a chopped cup of 107 grams gives about 2 grams of fiber and 52 milligrams of vitamin C, more than half the Daily Value.
Riced cauliflower works as a lighter stand in for rice. It’s an easy way to add volume and fiber to a bowl without changing the flavor much.
Cabbage
A cup of raw chopped green cabbage, about 89 grams, has 2.2 grams of fiber. Cooking concentrates it, but green cabbage stays the leanest of the four at 2.8 grams per cooked cup.
Choose savoy or red cabbage when you can. Both reach 4.1 grams per cooked cup, close to kale.
Sauerkraut, which is fermented cabbage, keeps a good share of the fiber at about 4.1 grams per cup. The tradeoff is salt: USDA data put a cup at roughly 939 milligrams of sodium, so it works best as a topping rather than a side dish.
Planning how these vegetables fit into your daily total? Our fiber calculator gives you a personal target to aim for.
How crucifers stack up against other vegetables
Crucifers aren’t the only high fiber vegetables, so it helps to see where they fall. This table puts the same cooked cup numbers next to popular vegetables from other families.
| Vegetable (1 cup cooked) | Family | Fiber | Calories |
|---|---|---|---|
| Artichoke | Daisy | 9.6 g | 89 |
| Brussels sprouts | Cruciferous | 6.4 g | 65 |
| Sweet potato | Morning glory | 6.3 g | 190 |
| Broccoli | Cruciferous | 5.2 g | 54 |
| Carrots | Carrot | 4.8 g | 54 |
| Spinach | Amaranth | 4.3 g | 41 |
| Corn | Grass | 4.0 g | 134 |
| Okra | Mallow | 4.0 g | 36 |
| Asparagus | Asparagus | 2.9 g | 32 |
| Onions | Onion | 2.9 g | 92 |
Artichokes beat every crucifer on fiber per cup, and sweet potatoes nearly tie Brussels sprouts. But neither matches the crucifers on calories: a cup of sweet potato carries about three times the energy of a cup of Brussels sprouts for the same fiber.
Corn is the clearest contrast. It has 4.0 grams per cup, less than cauliflower, with roughly four times the calories, which is why crucifers are such a strong pick when you want fiber without much energy.
The raw crucifers: salads, slaws and garnishes
Some cruciferous vegetables are mostly eaten raw. Their fiber per cup depends heavily on how much the leaves or slices weigh.
| Raw vegetable | Portion | Fiber | Calories |
|---|---|---|---|
| Kohlrabi | 1 cup | 4.9 g | 36 |
| Brussels sprouts | 1 cup (88 g) | 3.3 g | 38 |
| Broccoli, chopped | 1 cup (91 g) | 2.4 g | 31 |
| Green cabbage, chopped | 1 cup (89 g) | 2.2 g | 22 |
| Cauliflower, chopped | 1 cup (107 g) | 2.1 g | 27 |
| Radishes, sliced | 1 cup (116 g) | 1.9 g | 19 |
| Bok choy, shredded | 1 cup (70 g) | 0.7 g | 9 |
Kohlrabi is the hidden star. This crunchy bulb, a cousin of cabbage, gives 4.9 grams per raw cup, matching cooked cauliflower.
Bok choy and arugula sit at the light end. Arugula has 1.6 grams per 100 grams, but its leaves are so airy that a handful barely registers, which makes it more of a flavor booster than a fiber source.
Myth vs fact: does cooking destroy the fiber?
Myth: raw cruciferous vegetables have more fiber than cooked ones, so steaming or roasting wastes it.
Fact: cooking doesn’t remove fiber, it removes water and air. A raw cup of broccoli has 2.4 grams, while a cooked cup has 5.2, simply because more broccoli fits in the cup once it softens.
Cooking can lower heat sensitive vitamins. In USDA data, boiled kale keeps only about a fifth of raw kale’s vitamin C per 100 grams, so eating crucifers both raw and cooked across the week gives you the best of both. For fiber alone, cooked portions are the easier way to rack up grams.
Easy ways to eat more crucifers
- Roast Brussels sprouts or cauliflower florets until browned at the edges, then toss with lemon
- Shave raw Brussels sprouts or kohlrabi into a slaw with apple and a yogurt dressing
- Stir chopped kale or collards into soups and stews in the last 10 minutes
- Swap half the rice in a stir fry for riced cauliflower
- Add shredded red cabbage to tacos, grain bowls and wraps for crunch
Combining two crucifers in one dish adds up quickly. A cup each of roasted broccoli and Brussels sprouts gives 11.6 grams of fiber for under 120 calories.
Want more recipes that put broccoli, cabbage and their cousins front and center? Our recipe eBooks have plenty of easy, high-fiber ideas.
Going easy on your gut
Crucifers have a reputation for causing gas. Mayo Clinic notes that adding a lot of fiber too quickly can cause gas, bloating and cramping, and recommends increasing it gradually over a few weeks while drinking plenty of water.
If you’re new to these vegetables, start with half cup portions of cooked broccoli or cauliflower. Cooked crucifers are softer and easier to eat in bigger amounts than raw slaws, so build up from there.
What research is still asking
Much of the interest in cruciferous vegetables goes beyond fiber, to the compounds that form when glucosinolates break down. The National Cancer Institute notes that two of them, indole-3-carbinol and sulforaphane, have been studied most for their effects in the lab.
Studies in people have been mixed so far. Some have found lower cancer risk in certain groups of crucifer eaters, while many others have found little or no link, partly because diet is hard to measure precisely.
Future studies that track exactly what people eat, and how their bodies process these compounds, should clarify the picture. In the meantime, the fiber numbers are already settled, and a daily cup of crucifers is one of the easiest ways to move closer to your target.
Cruciferous vegetables and fiber: common questions
Which cruciferous vegetable has the most fiber?
Brussels sprouts lead, with 6.4 grams of fiber per cooked cup and 65 calories. Broccoli follows at 5.2 grams, then turnip greens at 5.0 and cauliflower at 4.9.
Is broccoli or cauliflower higher in fiber?
Broccoli edges ahead, with 5.2 grams per cooked cup versus 4.9 for cauliflower. Cauliflower has fewer calories, though, so it gives more fiber per calorie.
How much fiber is in a cup of Brussels sprouts?
A cooked cup has 6.4 grams of fiber. A raw cup, about 88 grams of whole sprouts, has 3.3 grams.
Does cabbage have a lot of fiber?
It depends on the type. Cooked green cabbage has 2.8 grams per cup, while savoy and red cabbage each have 4.1 grams.
Do cooked cruciferous vegetables have less fiber than raw?
No. Cooking doesn’t destroy fiber, and a cooked cup usually holds more than a raw cup because the vegetables shrink. Raw broccoli has 2.4 grams per cup and cooked broccoli has 5.2.
Is kohlrabi high in fiber?
Yes. A cup of raw kohlrabi has 4.9 grams of fiber and 36 calories, about the same as a cup of cooked cauliflower.
Why do cruciferous vegetables cause gas?
Adding a lot of fiber at once, from crucifers or any other food, can cause gas and bloating. Mayo Clinic suggests increasing fiber gradually over a few weeks and drinking plenty of water.
Sources
- U.S. Department of Agriculture and U.S. Department of Health and Human Services. “Food Sources of Dietary Fiber,” Dietary Guidelines for Americans, 2020 to 2025. dietaryguidelines.gov
- U.S. Department of Agriculture, Agricultural Research Service. “FoodData Central” (raw Brussels sprouts 170383, cauliflower 169986, broccoli, green cabbage, radishes 169276, pak choi 170390, arugula 169387, kale raw and boiled, sauerkraut). 2019. fdc.nal.usda.gov
- National Cancer Institute. “Cruciferous Vegetables and Cancer Prevention.” 2012. cancer.gov
- Mayo Clinic Staff. “Dietary fiber: Essential for a healthy diet.” Mayo Clinic. 2024. mayoclinic.org
