Onion vs. Red Bell Pepper

Nutrition comparison of Onion and Red Bell Pepper


Ever wonder how your favorite foods stack up against each other in terms of nutrition?

We compared the nutritional contents of onion versus red bell pepper (100g each) below using 2020 USDA and NIH data[1].

For a quick recap of significant nutrients and differences in onion and red bell pepper:

  • Red bell pepper has more riboflavin, niacin, pantothenic acid, Vitamin B6 and folate.
  • Red bell pepper is a great source of dietary fiber and potassium.
  • Red bell pepper is an excellent source of Vitamin A and Vitamin C.
Detailed nutritional comparison of onion and red bell pepper is analyzed below. You can also visualize the nutritional comparison for a custom portion or serving size and see how the nutrition compares.

USDA sources for nutritional information: Onion (Onions, raw) and Red Bell Pepper (Peppers, sweet, red, raw) . Have a correction or suggestions? Shoot us an email.


Image of Onion src
Image of Red Bell Pepper src

Calories and Carbs

calories

Onion and red bell pepper contain similar amounts of calories - onion has 40 calories per 100 grams and red bell pepper has 26 calories.

For macronutrient ratios, onion is heavier in carbs, lighter in fat and similar to red bell pepper for protein. Onion has a macronutrient ratio of 10:88:2 and for red bell pepper, 13:78:9 for protein, carbohydrates and fat from calories.

Macro Ratios from Calories:

Onion Red Bell Pepper
Protein 10% 13%
Carbohydrates 88% 78%
Fat 2% 9%
Alcohol ~ ~

carbohydrates

Onion and red bell pepper contain similar amounts of carbs - onion has 9.3g of total carbs per 100 grams and red bell pepper has 6g of carbohydrates.

dietary fiber

Red bell pepper is a great source of dietary fiber and it has 24% more dietary fiber than onion - onion has 1.7g of dietary fiber per 100 grams and red bell pepper has 2.1g of dietary fiber.

sugar

Onion and red bell pepper contain similar amounts of sugar - onion has 4.2g of sugar per 100 grams and red bell pepper has 4.2g of sugar.

Protein

protein

Onion and red bell pepper contain similar amounts of protein - onion has 1.1g of protein per 100 grams and red bell pepper has 0.99g of protein.

Fat

saturated fat

Both onion and red bell pepper are low in saturated fat - onion has 0.04g of saturated fat per 100 grams and red bell pepper has 0.06g of saturated fat.

Vitamins

Vitamin C

Red bell pepper is an excellent source of Vitamin C and it has 16 times more Vitamin C than onion - onion has 7.4mg of Vitamin C per 100 grams and red bell pepper has 127.7mg of Vitamin C.

Vitamin A

Red bell pepper is an excellent source of Vitamin A and it has more Vitamin A than onion - red bell pepper has 157ug of Vitamin A per 100 grams and onion does not contain significant amounts.

Vitamin E

Red bell pepper has 78 times more Vitamin E than onion - onion has 0.02mg of Vitamin E per 100 grams and red bell pepper has 1.6mg of Vitamin E.

Vitamin K

Onion and red bell pepper contain similar amounts of Vitamin K - onion has 0.4ug of Vitamin K per 100 grams and red bell pepper has 4.9ug of Vitamin K.

The B Vitamins

Red bell pepper has more riboflavin, niacin, pantothenic acid, Vitamin B6 and folate. Both onion and red bell pepper contain significant amounts of thiamin.

Onion Red Bell Pepper
Thiamin 0.046 MG 0.054 MG
Riboflavin 0.027 MG 0.085 MG
Niacin 0.116 MG 0.979 MG
Pantothenic acid 0.123 MG 0.317 MG
Vitamin B6 0.12 MG 0.291 MG
Folate 19 UG 46 UG

Minerals

calcium

Onion has 229% more calcium than red bell pepper - onion has 23mg of calcium per 100 grams and red bell pepper has 7mg of calcium.

iron

Onion and red bell pepper contain similar amounts of iron - onion has 0.21mg of iron per 100 grams and red bell pepper has 0.43mg of iron.

potassium

Red bell pepper is a great source of potassium and it has 45% more potassium than onion - onion has 146mg of potassium per 100 grams and red bell pepper has 211mg of potassium.

Antioxidants and Phytonutrients

flavonoids

Naturally occuring in fruits and vegetables, flavonoids are associated with many health benefits and used in a variety of medicinal and pharmaceutical applications. [2][3]

For specific flavonoid compounds, red bell pepper has more luteolin than onion per 100 grams, however, onion contains more isorhamnetin, kaempferol and quercetin than red bell pepper per 100 grams.

Onion Red Bell Pepper
apigenin 0.01 mg ~
luteolin 0.02 mg 0.61 mg
isorhamnetin 5.01 mg ~
kaempferol 0.65 mg 0.02 mg
myricetin 0.03 mg ~
Quercetin 20.3 mg 0.23 mg

carotenoids

Carotenoids are micronutrients commonly found in plants and some animal products. An example is beta-carotene, the notable carotenoid which is a popular source of Vitamin A.[4][5]

For specific types of carotenoids,

Onion Red Bell Pepper
beta-carotene 1 UG 1624 UG
lutein + zeaxanthin 4 UG 51 UG
alpha-carotene ~ 20 UG

Omega-3 and Omega-6

omega 3s

For omega-3 fatty acids, red bell pepper has more alpha linoleic acid (ALA) than onion per 100 grams.

Onion Red Bell Pepper
alpha linoleic acid 0.004 G 0.056 G
Total 0.004 G 0.056 G

omega 6s

Comparing omega-6 fatty acids, red bell pepper has more linoleic acid than onion per 100 grams.

Onion Red Bell Pepper
linoleic acid 0.013 G 0.1 G
Total 0.013 G 0.1 G



Customize your serving size


The comparison below is by weight, but sometimes 100g isn't that intuitive of a measurement for food. View a custom portion comparison (e.g. cups, oz, package).

You can try adding or subtracting the amount of either Onion or Red Bell Pepper .

Note: The specific food items compared are: Onion (Onions, raw) and Red Bell Pepper (Peppers, sweet, red, raw) .

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FAQ

Does onion or red bell pepper contain more calories in 100 grams?
Onion and red bell pepper contain similar amounts of calories - onion has 40 calories in 100g and red bell pepper has 26 calories.

Does onion or red bell pepper have more carbohydrates?
By weight, onion and red bell pepper contain similar amounts of carbs - onion has 9.3g of carbs for 100g and red bell pepper has 6g of carbohydrates.