Kale vs Spinach: Which is Better? A Complete Comparison

Kale and spinach are two superfoods often used together or in place of the other. Many people wonder if there’s much of a difference between the two. Let’s examine, what is the difference between kale and spinach?

Kale is a leaf cabbage belonging to a group of cabbage cultivars while spinach is a leafy green belonging to the Amaranthaceae family. Kale’s leaves are harder and coarser than spinach. Spinach is a dark green while kale’s color can range from light green to a violet-green. Kale tastes more bitter and spinach provides more nutrients.

This article will examine both foods including a side-by-side nutrient comparison. In addition, I’ll take a close look at their tastes, textures, prices, glycemic index, health benefits and if one can substitute for the other.

As a Certified Health Coach many clients have asked me about kale and spinach. In addition to coaching clients about them, I’ve purchased, researched and consumed both prior to, during and after writing this article.

The Difference Between Kale and Spinach

Both are nutritious, leafy greens often used interchangeably in recipes, but there are some key differences between the two. Kale is a member of the cabbage food category, and its leaves are hard and have a slightly bitter taste. 

In contrast, spinach is a member of the Amaranthaceae family, and its leaves are soft and have a milder taste but can be bitter also. 

Both are highly nutritious and low-calorie foods that provide a variety of vitamins and minerals with some fiber and protein1. However, they have different concentrations of nutrients2. 

Kale and spinach in bowls
Kale on the left spinach on the right

Kale vs Spinach Nutrition

The following table compares the nutrients per 100 grams.

Spinach, raw (100 g) Kale, raw (100 g)
Calories 23 35
Protein 2.86 g 2.92 g
Carbohydrates 3.63 g 4.42 g
Fiber 2.2 g 4.1 g
Fat 0.39 g 1.49 g
Sugar 0.42 g 0.80 g
Vitamin A 9,380 IU 4,480 IU
Beta-carotene 5,630 mcg 2,870 mcg
Vitamin C 28.1 mg 93.4 mg
Vitamin K 483 mcg 390 mcg
Vitamin D 0 IU 0 IU
Vitamin B6 0.19 mg 0.15 mg
Vitamin B9 (Folate) 194 mcg 62 mcg
Vitamin B1 (Thiamin) 0.08 mg 0.11 mg
Vitamin B2 (Riboflavin) 0.19 mg 0.35 mg
Vitamin B3 (Niacin) 0.72 mg 1.18 mg
Vitamin B5 (Pantothenic Acid) 0.07 mg 0.37 mg
Magnesium 79 mg  33 mg
Phosphorous 49 mg  55 mg
Potassium 558 mg 348 mg
Iron 2.71 mg 1.60 mg
Copper 0.13 mg 0.05 mg
Calcium 99 mg 254 mg
Zinc 0.53 mg 0.39 mg

Nutrient Resources34

Looking at the nutrient table above it’s difficult to determine if one is better than the other, the nutrients are pretty similar. Let’s examine which is healthier.

Kale and spinach are nutrient dense and provide a similar number of nutrients. For this reason, they are equally healthy and both should be part of a well-rounded, healthy diet.

There are some nutrients kale is higher in. It provides a higher percentage of protein, fiber, vitamin C, thiamin, niacin, riboflavin, B5, phosphorous and calcium.

Spinach provides a higher percentage of vitamin A, beta carotene, vitamin K, B6, folate, magnesium, potassium, iron, copper and zinc.

Choosing one over the other may depend on your particular goals and lifestyle category. Let’s examine some of those goals next.

I use spinach more but I purchase and consume both almost daily. I use baby spinach for salads and smoothies. I often use the frozen varieties which I add directly into a smoothie prior to mixing all the ingredients.

The following video compares both vegetables.

Which to Choose

Low-carb or Keto Diet

The number one thing to look at first while on a low-carb diet is the carbohydrates. Therefore, let’s examine the carbohydrates provided.

Kale has 0.79 more carbohydrates than spinach per 100 grams. While this doesn’t sound like much of a difference, it has 21% more carbohydrates. On a keto diet a small difference may mean a lot. Therefore, spinach is better for low-carb diets.

Weight Loss

If you’re counting calories to lose extra fat around the middle, you may be wondering which one benefits weight loss.

Spinach contains 12 fewer calories than kale per 100 grams. While this doesn’t sound like much of a difference, it results in a 50% difference in calories. Therefore, spinach is better for weight loss if you’re counting calories.

Gluten Free

If you’re consuming a gluten free diet or have celiac disease, this can make or break your choice between the two. Which is gluten free?

Kale and spinach are gluten free. Therefore, if you have celiac disease, both of them are good options.

Bodybuilding

If you’re trying to gain lean muscle mass, your carbohydrate and protein intake are important. The extra protein helps to repair and build new muscle after a workout. The extra carbohydrates help to fuel energy and increase exercise performance when lifting weights.

Let’s examine which is better for bodybuilding.

Kale provides 0.6 more grams of protein per 100 grams, approximately 2% more than spinach. Kale provides 0.79 more carbohydrates per 100 grams, 21% more. It also provides a little more calories which can help when bulking up.

Therefore, kale is better for bodybuilding.

spinach and kale nutrient comparison

Taste and Texture

Sometimes the difference in nutrients or calories may not matter, and the decision to choose one of the foods comes down to how good it tastes. Therefore, let’s examine the difference in the taste and texture.

Kale has a slightly bitter taste compared to the milder spinach. Spinach may taste bitter to some people but not as much as kale. Kale leaves are harder and chewier than the softer spinach leaf. When kale is cooked, it retains more of its tougher texture than spinach which becomes softer.

I wanted to conduct original research and find out what real people like you thought about the taste of kale and spinach. Therefore, I polled my clients, readers and people belonging to food groups and asked, what tastes better?

  • 59% said they preferred the taste of spinach.
  • 34% said they preferred the taste of kale.
  • 7% said they had no preference.

Home Taste Test

To conduct more research I setup and participated in a taste test at home. Two out of three of us chose spinach for it better and less bitter flavor.

Substituting

For many different reasons, you may want to use one of the two foods in a recipe calling for the other food. For these reasons, you’ll need to know if they can substitute for each other.

Kale and spinach can substitute for each other although the texture will be different due to the coarser kale. When substituting in salads use a one to one ratio. When cooking use more spinach due to how it breaks down while cooked.

Substitute both in the following dishes:

  • Salads
  • Smoothies
  • Curries
  • Casseroles
  • Soups
  • Sandwiches
  • Tacos

Additional Tips:

  • When using kale in salads, massaging the leaves can make them more tender and less hard. In addition, always destem it.
  • Kale can be cut up finer so it cooks thoroughly and to soften up quicker if desired.
  • To achieve a softer texture from kale, cook it longer.

You may want to use both of them together in the same salad or dish. Some of the food manufacturers have made this easy for you by selling them together in the same container or bag in the produce section.

The following video explains to you an easy way to make a kale salad.

Prices

How much food cost is important to most people. Lately, it seems the price of grocery items keeps getting higher. Therefore, let’s take a close look the prices, kale vs spinach.

Fresh kale costs more money per ounce than spinach. The cost for fresh kale averages $0.24 per ounce and spinach averages $0.16 per ounce. 

To conduct some original research, I visited some local supermarkets and checked the prices of both. Here are my findings.

First I visited a Walmart Supercenter:

  • Marketside bagged fresh spinach
    • 10 ounce bag for $1.98. Equals $0.20 per ounce
  • Marketside fresh kale
    • 16 ounce container for $4.84. Equals $0.30 per ounce

I then checked my local Shoprite supermarket:

  • Bowl and basket chopped spinach
    • 10 ounce bag for $1.29. Equals $0.13 per ounce
  • Bowl and basket kale
    • 16 ounce bag for $2.99. Equals $0.18 per ounce
checking kale and spinach prices at my local supermarket
Checking kale and spinach prices at my local supermarket

Glycemic Index for Kale and Spinach

Blood sugar spikes may lead to health complications over time ((National Institute of Diabetes and Digestive and Kidney Diseases: Know Your Blood Sugar Numbers: Use Them to Manage Your Diabetes)). For this reason, avoiding blood sugar spikes as often as possible is an important part of a healthy diet.

The glycemic index measures how fast food raises blood sugar levels ((Harvard Health Publishing: Glycemic index for 60+ foods)). Foods on the GI scale are categorized as:

  • Low-GI foods: 55 or under
  • Medium-GI foods: 56-69
  • High-GI foods: 70 or over

How blood sugars levels are affected:

  • Foods with a glycemic index 70 or more cause a quicker spike in blood sugar levels.
  • Foods with a glycemic index 56 to 69 cause a moderate spike in blood sugar levels.
  • Foods with a glycemic index 55 or less cause a slow spike in blood sugar levels.

Kale and spinach are both low glycemic foods and shouldn’t cause any spikes in blood sugar. Besides the two, all leafy greens have a low glycemic index, almost unmeasurable in some varieties. This increases their benefits.

Kevin Garce checking spinach and kale in his local supermarket.
Checking spinach and kale in the produce section of my local supermarket

If you have any questions about this article don’t hesitate to email us. You can find an email on our contact page.

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  1. Wikipedia: Kale []
  2. Wikipedia: Spinach []
  3. USDA: Spinach, raw []
  4. USDA: Kale, raw []

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