Spinach vs Romaine: Which is Better? An Ultimate Comparison

Part of my job as a Certified Health Coach is to inform people about healthy foods like spinach and romaine lettuce. Many of my clients ask me if one is superior to the other. Let’s answer which is better, spinach or romaine?

Spinach is better than romaine due to its higher percentage of vitamins, minerals, protein and fiber. Spinach provides 600% more vitamin C, 200% more calcium and 477% more iron than romaine. Spinach is easier to find in stores and costs less per ounce making it slightly more affordable.

This article will start with a side-by-side nutrient comparison of the two leafy greens. In addition, I’ll examine their tastes, textures, prices, glycemic indexes, health benefits and whether one can substitute for the other.

I’ve purchased, researched and consumed both leafy greens prior to, during and sometimes after writing this article.

Spinach vs Romaine Lettuce: Nutritional Profile Comparison

The following table compares the nutrients contained in each one per 100 grams.

Spinach, raw (100 g) Romaine, raw (100 g)
Calories 23 17
Protein 2.86 g 1.23 g
Carbohydrates 3.63 g 3.29 g
Fiber 2.2 g 2.1 g
Fat 0.39 g 0.30 g
Sugar 0.42 g 1.19 g
Vitamin A 9,380 IU 8,710 IU
Beta-carotene 5,630 mcg 5,230 mcg
Vitamin C 28.1 mg 4.0 mg
Vitamin K 483 mcg 102 mcg
Vitamin D 0 IU 0 IU
Vitamin B6 0.19 mg 0.07 mg
Vitamin B9 (Folate) 194 mcg 136 mcg
Vitamin B1 (Thiamin) 0.08 mg 0.07 mg
Vitamin B2 (Riboflavin) 0.19 mg 0.07 mg
Vitamin B3 (Niacin) 0.72 mg 0.31 mg
Vitamin B5 (Pantothenic Acid) 0.07 mg 0.14 mg
Magnesium 79 mg  14 mg
Phosphorous 49 mg  30 mg
Potassium 558 mg 247 mg
Iron 2.71 mg 0.97 mg
Copper 0.13 mg 0.05 mg
Calcium 99 mg 33 mg
Zinc 0.53 mg 0.23 mg

Nutrient Resources 1 2

Both contain many of the same nutrients. After examining the table above let’s determine which is healthier.

Spinach is healthier than romaine lettuce because it provides more protein, fiber, vitamin A, vitamin C, vitamin K, B6, folate, riboflavin, niacin, magnesium, phosphorus, potassium, iron, copper, calcium and zinc.

Romaine provides more B5 and fewer calories, carbohydrates and total fat.

I typically use spinach at home for salads, smoothies and entrees due to its nutrients.

In almost every category, spinach is nutritionally superior to lettuce. Find out how these nutrients benefit health further down in this article.

The following video compares the benefits of spinach and romaine lettuce.

Which to Choose

Based on the nutrients just discussed, one of the two foods may be more beneficial for your particular goal. Let’s take a look at the more popular goals and which food is better for them.

Weight Loss and Green Vegetables

If weight loss is the goal, the number of calories per serving is important. Let’s examine how many calories per serving each one contains.

Spinach has 23 calories, and romaine lettuce has 17 calories per 100 grams. Romaine provides 6 fewer calories. While this number may not seem like much, it equals 35% less calories making it better for weight loss.

When counting calories every little bit may help as the total is calculated for the day.

Low-carb or Keto Diets

If you’re currently consuming low-carb foods or considering one of these diets, the number of carbohydrates may make a huge difference. Therefore, let’s examine which one has more carbohydrates.

Spinach has 3.63 grams of carbohydrates, and romaine has 3.29 per 100 grams, 10% fewer making it better for low-carb diets.

The difference isn’t large but when limiting the total amount, every gram can make a difference at the end of the day.

anti-aging spinach smoothie
Spinach smoothie

Gluten Free

For people who have celiac disease, whether one food contains gluten will automatically make the decision which to choose. Some people prefer following a gluten free diet, therefore it’s important also.

Spinach and romaine lettuce are gluten free. Therefore, both foods are good options for a gluten free diet.

Bodybuilding and Spinach Nutrition

If gaining lean muscle mass is your goal then the amount of protein and carbohydrates may matter to you.

Healthy carbohydrates help to increase performance and fuel energy when exercising or lifting weights. It’s why marathon runners consume many carbs the day and night before the big race.

Any extra protein helps to build and repair muscle after putting them through a good workout. Therefore, let’s take a closer look at which is better for bodybuilding.

Spinach is better than romaine for bodybuilding due to its higher percentage of protein and carbohydrates. It provides 2.86 grams of protein and romaine 1.23 grams per 100 grams. It provides 133% more protein per 100 grams.

In addition, it provides 10% more carbohydrates and 35% more calories which may help when trying to bulk up.

spinach and romaine nutrient comparison

Tastes and Textures

Some foods taste undesirably to some people. In this situation, no matter how many nutrients the food has, that food may remain on the store shelf instead of in the shopping cart.

Therefore, let’s take a close look at how the taste and texture of each one compares.

Romaine has a refreshing, juicy taste and is a little bitter like spinach. Raw spinach is drier and tastes grassier than romaine lettuce. Romaine is crispier than raw spinach which is softer raw or cooked.

I wanted to get the opinion of real people like you by conducting some original research. So I reached out to some of my clients, readers and members of food groups and asked, which one tastes better?

  • 34% said they preferred the taste of spinach.
  • 58% said they preferred the taste of romaine.
  • 8% said it depended on their mood.

To conduct more original research I setup a blind taste test at home. We chopped both into equal size leaves to help avoid detection. I chose the romaine due to its crispier texture and moist content.

In the battle of taste, romaine was the winner. Many people also stated, if health or nutrients were the priority, they would choose spinach first even though they preferred the taste of the other.

Cooked spinach as a side dish.
Cooked spinach as a side dish

Substituting for Lettuce

Sometimes you may only have one available at home and don’t want to run out to the store. In this situation or any other time when you may want to substitute, you’ll wonder if they can be used for each other.

Spinach and romaine lettuce can substitute for each in raw or cooked dishes. They can also substitute for one another in gluten free recipes. When substituting, use a one to one ratio. When cooking, both of them will shrink in volume.

Other substitutes include the following:

  • Swiss chard
  • Bok choy
  • Green leaf lettuce
  • Butterhead lettuce
  • Watercress
  • Collard greens
  • Iceberg
  • Kale
  • Arugula
  • Beet greens

Which Cost More?

The price of foods commonly purchased is important to most people, especially with the inflation we’re experiencing lately. Let’s take a detailed look at how much each one costs.

Romaine lettuce costs more than spinach. The average price for romaine is $0.22 per ounce. The average price for spinach is $0.18 per ounce.

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

First I checked Walmart:

  • Marketside bagged fresh spinach
    • 10 ounce bag $1.98. Equals $0.20 per ounce
  • Marketside bagged leafy romaine lettuce
    • 10 ounce bag $2.78. Equals $0.28 per ounce

I then checked my local Shoprite supermarket:

  • Fresh spinach bundle
    • 12 ounces for $1.87. Equals $0.16 per ounce
  • Romaine lettuce bundle
    • 20 ounces for $3.11. Equals $0.16 per ounce

spinach and romaine comparison

Glycemic Index

Blood sugar spikes may lead to health complications over time 3. 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 4Foods 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.

Let’s examine which food has a higher glycemic index.

Spinach and romaine lettuce have low glycemic indexes and are considered low glycemic index foods. Therefore, either food is a good choice to avoid blood sugar spikes.

Find out if collard greens are better in my article.

checking leafy green prices at my local supermarket
Checking leafy green lettuce and spinach prices at my local supermarket

Health Benefits

This section will examine the health benefits of the nutrients provided by both foods. Each section includes the benefits of each nutrient and a breakdown of the percentages provided by each food.

Spinach Health Benefits

In the following video an accredited hospital and doctor explain the spinach nutrition and benefits.

Vitamin C

  • Spinach contains more vitamin C (an antioxidant) per 100 grams, 600% more.

Vitamin C acts as an antioxidant and helps with the following:

  • Prevent cell damage.
  • May help boost the immune system.
  • Collagen production.
  • Help heal wounds.
  • Increases iron absorption.
  • Help maintain health gums.

Magnesium

  • Spinach provides 460% more magnesium per 100 grams.

Magnesium helps the body control the following:

  • Nerve function
  • Blood pressure
  • Muscle function
  • Insomnia
  • Blood sugar

Magnesium helps keep blood pressure levels stable and balanced. Recent scientific research examined previous studies and concluded magnesium supplementation decreased systolic and diastolic blood pressure 5.

Many people supplement with magnesium in the evening because it helps calm the whole body including blood vessels.

Find out if Swiss chard has more nutrients in my article. You may be surprised.

romaine lettuce in the supermarket
Picking romaine lettuce in the supermarket

Potassium

  • Spinach provides 126% more potassium per 100 grams.

According to Harvard Health, a number of studies have shown a connection between low potassium levels and high blood pressure 6. The more potassium, the more sodium your body will lose.

Calcium

  • Spinach provides 110% more calcium per 100 grams.

Calcium helps the following:

  • Helps nerve function.
  • Help the muscles to function properly.
  • Build and maintain strong bones.

In addition, calcium is important for the heart and blood pressure. Harvard Health reports calcium helps maintain blood pressure by helping in the controlling of the relaxing and tightening of blood vessels 7.

Vitamin K

  • Spinach provides 374% more vitamin K per 100 grams.

Vitamin K comes in two forms. Phylloquinone is the one found in both vegetables.

Vitamin K helps to make various proteins needed to help with the following:

  • Heart disease
  • Blood clotting
  • Bone health

Vitamin K, through the production of proteins, help to prevent hardening or calcification of the arteries 8.

Iron

  • Spinach provides 477% more iron per 100 grams.

Iron is a necessary part of any healthy diet 9 and may help with the following:

  • Vital for development and growth.
  • Is essential the creation of red blood cells.
  • Help some hormones remain balanced.
  • Help the immune system.

Find out if kale has more nutrients in my article. It’s a veggie powerhouse comparison.

The following video describes the best way to cut lettuce.

B Vitamins

Spinach provides a higher percentage of B6, folate, thiamin, niacin and riboflavin. Romaine provides a higher percentage of B5 but also contains the other B vitamins.

The B vitamins provided include the following:

  1. B1 (thiamin)
  2. B2 (riboflavin)
  3. B3 (niacin)
  4. B5
  5. B6
  6. B9 (folate)

B vitamins help support the following:

  • Brain function.
  • Digestion.
  • Nerve function.
  • Cardiovascular disease.
  • Red blood cells.
  • Energy levels.

Vitamin A & Beta Carotene

  • Spinach provides 7.7% more vitamin A per 100 grams.

Spinach provides 7.6% more beta carotene per 100 grams.

Beta-carotene is a compound present in both foods. The body converts beta-carotene into vitamin A.

According to scientific studies, vitamin A helps the eyes when it comes to dim light vision and dry eyes 10.

Besides eye health, an increased number of vitamin A has been shown to fight and prevent cardiovascular disease, which is the leading cause of death in the United States 11.

In addition, vitamin A is a powerful antioxidant that can help reduce cellular damage by controlling the negative effects of free radicals 12.

Dietary Fiber

Both green vegetables contains almost an equal number of dietary fiber. When examining each one’s nutritional profile, this is one of the few where the lettuce romaine holds its own.

Spinach salad with walnuts and oranges.
Spinach salad with walnuts and oranges

Compare the benefits of baby spinach and regular in my article.

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

Read More Spinach Food vs Food Articles

Spinach vs Broccoli: Which is Better? A Complete Comparison

Frozen Spinach vs Fresh: Which is Better? A Comparison

Raw Spinach vs Cooked Spinach: Which is Better? A Comparison

Arugula vs Spinach: Which is Better? A Complete Comparison

Organic Spinach vs. Regular Spinach: What’s The Difference?

Spinach vs Lettuce: Which is Better? A Complete Comparison

Article Resources: Foods For Anti-Aging follows strict guidelines to ensure our content is the highest journalistic standard. It's our mission to provide the reader with accurate, honest and unbiased guidance. Our content relies on medical associations, research institutions, government agencies and study resources. Learn more by reading our editorial policy.
  1. USDA: Spinach, raw[]
  2. USDA: Lettuce, cos or romaine, raw[]
  3. National Institute of Diabetes and Digestive and Kidney Diseases: Know Your Blood Sugar Numbers: Use Them to Manage Your Diabetes[]
  4. Harvard Health Publishing: Glycemic index for 60+ foods[]
  5. National Center for Biotechnology Information: Effect of magnesium supplementation on blood pressure: a meta-analysis[]
  6. Harvard Health: Potassium lowers blood pressure[]
  7. Harvard Health: Key minerals to help control blood pressure[]
  8. Harvard T.H. Chan: Vitamin K[]
  9. National Institutes of Health: Iron[]
  10. National Center for Biotechnology Information: Nutrients for the aging eye[]
  11. National Center for Biotechnology Information: Antioxidant potentials of vitamin A and carotenoids and their relevance to heart disease[]
  12. National Center for Biotechnology Information: Free radicals, antioxidants and functional foods: Impact on human health[]

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