Kale or Spinach: Which Greens Reign Supreme? Nutritionists Weigh In

While kale and spinach share similarities in look, taste, and nutrient profile, these leafy greens are distinct in many ways. So, what sets kale apart from spinach? Kale belongs to the cruciferous vegetable group—part of the Brassicaceae family, which also includes broccoli, Brussels sprouts, cabbages, and arugula. Spinach, on the other hand, is a chenopod, a category that encompasses Swiss chard, beets, and quinoa. Both families can be consumed raw but differ in chemical composition, texture, and nutritional value. 

It’s worth noting that kale comes in various forms—green kale, curly kale, lacinato kale (also known as dinosaur kale or Tuscan kale), and flat leaf kale—each with slight nutritional variations. Spinach is available either with stems or as pre-washed, stemless options. Regardless of the type, both kale and spinach are incredibly healthy, and choosing the one that suits your taste and availability can be a smart, nutritious decision. 

Kale is generally in season from September to February, whereas spinach peaks in early spring through mid-summer. However, both greens are accessible year-round in grocery stores, found in the fresh produce section or the frozen food aisle. 

“Kale and spinach are both nutritional superstars, but they excel in different areas,” explains Kristy Baumann, RDN, LDN. Discover the unique benefits of each and how to select kale or spinach based on your dietary needs. Can’t pick one? Incorporate both into your meals. After all, greens are incredibly beneficial for your health! 

Benefits of Kale

According to the USDA, here are the nutritional details for 1 cup (20.6 grams) of raw kale. 

MacronutrientsCalories: 7 caloriesTotal Fat: 0 gSaturated Fat: 0 g Cholesterol: 0 mg Carbohydrates: 1 g Fiber: 1 g Sugar: 0 g Protein: 1 g

Micronutrients: Calcium: 4 mgPotassium: 2 mgSodium: 11 mgIron: 2 mgVitamin A: 6 mcg RAE Vitamin C: 22 mg Vitamin D: 0 mcg

Kale is a nutrient-dense, low-calorie vegetable that’s also low in carbs, offering a good amount of fiber, iron, and calcium. 

“Kale is rich in antioxidants, such as beta-carotene and flavonoids, which combat inflammation and reduce the risk of chronic illnesses,” Baumann explains. “It’s an excellent source of vitamin K, essential for bone strength and blood clotting. Its fiber aids in digestive health, while vitamin A contributes to glowing skin and optimal vision.” 

Benefits of Spinach 

Next, let’s examine the USDA’s nutritional profile for spinach, based on a 1-cup (30-gram) serving. 

MacronutrientsCalories: 7 Total Fat: 0 g Saturated Fat: 0 g Cholesterol: 0 mgCarbohydrates: 1 g Dietary Fiber: 1 g Total Sugars: 0 g Protein: 1 g

MicronutrientsCalcium: 2 mg Potassium: 4 mg Sodium: 24 mg Iron: 5 mg Vitamin A: 16 mcg RAE Vitamin C: 9 mg Vitamin D: 0 mcg

Spinach is a low-calorie, low-carb vegetable that offers fiber, protein, and essential nutrients like potassium, calcium, and a variety of vitamins. 

“Spinach is an excellent source of iron, crucial for energy metabolism and oxygen delivery in the body—particularly beneficial for those with active lifestyles,” Baumann notes. It’s also packed with magnesium, which supports muscle and nerve health, and folate, essential for cell regeneration. Additionally, spinach contains lutein and zeaxanthin, antioxidants that safeguard eye health and prevent age-related vision issues.” 

Kale vs. Spinach: Which Green Reigns Supreme in Nutrition? 

The healthiest green is ultimately the one you enjoy eating, though kale and spinach each offer unique nutritional advantages.

“Determining which green is 'healthier' depends on your individual dietary goals,” explains Baumann. “Kale is richer in vitamin C, whereas spinach provides more iron and magnesium. Kale is excellent for strengthening immunity with its vitamin C content, while spinach is better suited for enhancing muscle performance or energy production due to its iron levels.”

Ways to Incorporate More Kale and Spinach into Your Diet 

Kale and spinach can be incorporated into a variety of savory and spicy meals. “I enjoy mixing spinach or kale into soups, pasta dishes, stir-fries, scrambled eggs, and even burger patties,” Baumann shares. “For a crunchy treat, bake kale into chips with a dash of seasoning.” Both greens can also be blended into smoothies or green juices for an extra nutrient boost. 

Opting for pre-washed and packaged baby spinach or baby kale makes it easier to incorporate these greens into meals quickly (as they wilt fast!). They’re perfect for adding to cold dishes like wraps, grain bowls, or salads, such as this Baby Kale and Chicken Caesar. ”Baby kale and baby spinach are simply younger forms of the plants,” Baumann notes. “Nutritionally, they remain potent, delivering similar vitamins and minerals, though baby kale may have a bit less fiber compared to mature kale.”

Keeping pre-cooked and chopped frozen spinach or kale in your freezer is a convenient way to enhance various recipes, such as these Grilled Chicken and Spinach Quesadillas or this Lentils, Kale, and Sausage Soup.