Green peas, Brussels sprouts, and spinach are among the vegetables with the most protein, though even the highest-protein vegetables top out around 3 to 9 grams per cooked cup. That’s modest compared to meat or beans, but vegetables can meaningfully contribute to your daily protein intake, especially when you eat them in volume or combine them with grains, nuts, and legumes.
For reference, most adults need about 0.8 grams of protein per kilogram of body weight each day. That works out to roughly 55 grams for a 150-pound person. No single vegetable will get you there on its own, but several can add a surprising amount to each meal.
The Vegetables With the Most Protein
Green peas stand in a category of their own. One cup of cooked green peas delivers about 8.6 grams of protein, which rivals what you’d get from a cup of milk. Peas are technically a legume, but most people treat them as a vegetable, and they show up in frozen vegetable mixes everywhere. They’re the single easiest way to add protein to a stir-fry, soup, or pasta without changing the flavor much.
After peas, the next tier of high-protein vegetables clusters between 2 and 4 grams per 100-gram serving (roughly a cup raw). Here’s how they compare:
- Alfalfa sprouts: 4 g protein per 100 g, only 23 calories
- Brussels sprouts: 3.4 g protein per 100 g, 43 calories
- Collard greens: 3 g protein per 100 g, 32 calories
- Spinach: 2.9 g protein per 100 g, 23 calories
- Mustard greens: 2.9 g protein per 100 g, 27 calories
- Kale: 2.9 g protein per 100 g, 43 calories
- Broccoli: 2.8 g protein per 100 g, 34 calories
- Watercress: 2.3 g protein per 100 g, 11 calories
- Asparagus: 2.2 g protein per 100 g, 20 calories
- Cauliflower: 1.9 g protein per 100 g, 25 calories
These numbers are for raw vegetables. Cooking concentrates them (a cup of cooked spinach weighs far more than a cup of raw), so a plate of sautéed greens often delivers more protein than you’d expect from the raw figures.
Protein Per Calorie: Where Vegetables Shine
The real advantage of vegetable protein isn’t the total grams. It’s how much protein you get relative to calories. Spinach provides 2.9 grams of protein for just 23 calories per 100 grams. Kale has nearly the same protein (2.9 grams) but costs you 43 calories, almost double. Watercress is the most extreme example: 2.3 grams of protein for only 11 calories, making it one of the most protein-dense foods on the planet by calorie count.
This matters if you’re trying to increase protein without increasing calories overall. Loading half your plate with broccoli, spinach, or Brussels sprouts adds several grams of protein to a meal for almost no caloric cost. Over three meals and a couple of snacks, that can easily total 15 to 20 extra grams per day.
Cruciferous Vegetables Compared
Broccoli, cauliflower, Brussels sprouts, and kale all belong to the cruciferous family, and they’re among the most commonly eaten high-protein vegetables. Brussels sprouts lead the group at 3.4 grams per 100 grams. A cup of raw broccoli (about 91 grams) has 2.5 grams of protein, while a cup of raw cauliflower (about 107 grams) has 2 grams. The difference is small, but broccoli edges out cauliflower in both protein and fiber.
Roasting any of these concentrates their flavor and makes it easy to eat larger portions. A generous side of roasted Brussels sprouts, around two cups cooked, can add 5 to 6 grams of protein to dinner.
The Amino Acid Question
Protein is made of amino acids, and your body needs nine specific ones from food. Most vegetables are low in one called methionine, which means their protein alone isn’t “complete” in the way that eggs or chicken are. Among common plant foods, potatoes are one of the few with a balanced amino acid profile on their own.
This sounds like a bigger problem than it actually is. You don’t need complete protein at every meal. Your body pools amino acids from everything you eat throughout the day. Vegetables tend to be low in methionine, while grains, nuts, and seeds tend to be low in a different amino acid called lysine. Eating both over the course of a day gives you the full set. A lunch with broccoli and rice, followed by an afternoon snack with almonds, covers all nine essential amino acids without any careful planning.
Plant proteins in general tend to be rich in certain amino acids that animal proteins don’t always provide as generously, particularly tryptophan and phenylalanine. So mixing plant and animal sources, or combining different plant sources, gives you a broader nutritional profile than relying on any single food.
Practical Ways to Add More
The simplest approach is volume. A small garnish of broccoli adds a gram of protein. A heaping two-cup side adds five or six. Treating vegetables as a main component of the plate rather than a decoration makes the math work in your favor.
Some specific strategies that add up quickly:
- Blend spinach or kale into smoothies. Two large handfuls of raw spinach (about 100 grams) adds nearly 3 grams of protein and barely changes the taste.
- Use peas as a base. Stir a cup of frozen peas into pasta, grain bowls, or soups for an instant 8.6-gram protein boost.
- Snack on sprouts. Alfalfa sprouts have 4 grams of protein per 100 grams and work well on sandwiches or salads.
- Pair vegetables with grains or nuts. This covers the amino acids that vegetables lack. Think broccoli with quinoa, spinach salad with walnuts, or asparagus alongside brown rice.
Vegetables will never compete with chicken breast or lentils as a primary protein source, but they don’t need to. When you eat them consistently and in generous portions, they contribute a meaningful share of your daily protein while also delivering fiber, vitamins, and minerals that concentrated protein sources often lack.