Watermelon vs. Onion

Nutrition comparison of Watermelon and Onion


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

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

For a quick recap of significant nutrients and differences in watermelon and onion:

  • Onion has more Vitamin B6 and folate.
Detailed nutritional comparison of watermelon and onion 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: Watermelon (Watermelon, raw) and Onion (Onions, raw) . Have a correction or suggestions? Shoot us an email.


Image of Watermelon src
Image of Onion src

Calories and Carbs

calories

Watermelon and onion contain similar amounts of calories - watermelon has 30 calories per 100 grams and onion has 40 calories.

For macronutrient ratios, watermelon is lighter in protein and similar to onion for carbs and fat. Watermelon has a macronutrient ratio of 7:90:4 and for onion, 11:87:3 for protein, carbohydrates and fat from calories.

Macro Ratios from Calories:

Watermelon Onion
Protein 7% 11%
Carbohydrates 90% 87%
Fat 4% 3%
Alcohol ~ ~

carbohydrates

Watermelon and onion contain similar amounts of carbs - watermelon has 7.6g of total carbs per 100 grams and onion has 9.3g of carbohydrates.

dietary fiber

Onion has 325% more dietary fiber than watermelon - watermelon has 0.4g of dietary fiber per 100 grams and onion has 1.7g of dietary fiber.

sugar

Watermelon and onion contain similar amounts of sugar - watermelon has 6.2g of sugar per 100 grams and onion has 4.2g of sugar.

Protein

protein

Watermelon and onion contain similar amounts of protein - watermelon has 0.61g of protein per 100 grams and onion has 1.1g of protein.

Fat

saturated fat

Both watermelon and onion are low in saturated fat - watermelon has 0.02g of saturated fat per 100 grams and onion has 0.04g of saturated fat.

Vitamins

Vitamin C

Watermelon and onion contain similar amounts of Vitamin C - watermelon has 8.1mg of Vitamin C per 100 grams and onion has 7.4mg of Vitamin C.

Vitamin A

Watermelon has more Vitamin A than onion - watermelon has 28ug of Vitamin A per 100 grams and onion does not contain significant amounts.

Vitamin E

Watermelon and onion contain similar amounts of Vitamin E - watermelon has 0.05mg of Vitamin E per 100 grams and onion has 0.02mg of Vitamin E.

Vitamin K

Watermelon and onion contain similar amounts of Vitamin K - watermelon has 0.1ug of Vitamin K per 100 grams and onion has 0.4ug of Vitamin K.

The B Vitamins

Onion has more Vitamin B6 and folate. Both watermelon and onion contain significant amounts of thiamin, riboflavin, niacin and pantothenic acid.

Watermelon Onion
Thiamin 0.033 MG 0.046 MG
Riboflavin 0.021 MG 0.027 MG
Niacin 0.178 MG 0.116 MG
Pantothenic acid 0.221 MG 0.123 MG
Vitamin B6 0.045 MG 0.12 MG
Folate 3 UG 19 UG

Minerals

calcium

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

iron

Watermelon and onion contain similar amounts of iron - watermelon has 0.24mg of iron per 100 grams and onion has 0.21mg of iron.

potassium

Watermelon and onion contain similar amounts of potassium - watermelon has 112mg of potassium per 100 grams and onion has 146mg 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, watermelon has more luteolin than onion per 100 grams, however, onion contains more isorhamnetin and quercetin than watermelon per 100 grams. Both watermelon and onion contain significant amounts of kaempferol.

Watermelon Onion
luteolin 0.46 mg 0.02 mg
kaempferol 0.45 mg 0.65 mg
apigenin ~ 0.01 mg
isorhamnetin ~ 5.01 mg
myricetin ~ 0.03 mg
Quercetin ~ 20.3 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, both watermelon and onion contain small amounts of lutein + zeaxanthin.

Watermelon Onion
beta-carotene 303 UG 1 UG
lycopene 4532 UG ~
lutein + zeaxanthin 8 UG 4 UG

Omega-3 and Omega-6

omega 6s

Comparing omega-6 fatty acids, both watermelon and onion contain small amounts of linoleic acid.

Watermelon Onion
linoleic acid 0.05 G 0.013 G
Total 0.05 G 0.013 G



Customize your serving size


The comparison below is by common portions, e.g. cups, packages. You can also see a more concrete comparison by weight at equal weight (by grams) comparison.

Note: The specific food items compared are: Watermelon (Watermelon, raw) and Onion (Onions, raw) .

Watermelon g

()
Daily Values (%)

Onion g

()
KCAL %
calories
KCAL %
G %
carbohydrates
G %
G %
dietary fiber
G %
G sugar G
G %
total fat
G %
G %
saturated fat
G %
G monounsaturated fat G
G polyunsaturated fat G
G trans fat G
MG cholesterol MG
MG %
sodium
MG %
Vitamins and Minerals
UG %
Vitamin A
UG %
MG %
Vitamin C
MG %
IU %
Vitamin D
IU %
MG %
calcium
MG %
MG %
iron
MG %
MG %
magnesium
MG %
MG %
potassium
MG %
MG %
thiamin (Vit B1)
MG %
MG %
riboflavin (Vit B2)
MG %
MG %
niacin (Vit B3)
MG %
MG %
Vitamin B6
MG %
MG %
pantothenic acid (Vit B5)
MG %
UG %
folate (Vit B9)
UG %
UG %
Vitamin B12
UG %
MG %
Vitamin E
MG %
UG %
Vitamin K
UG %
G %
protein
G %
UG %
biotin (Vit B7)
UG %
MG %
choline
MG %
MG %
chlorine
MG %
UG %
chromium
UG %
MG %
copper
MG %
UG %
fluoride
UG %
UG %
iodine
UG %
MG %
manganese
MG %
UG %
molybdenum
UG %
MG %
phosphorus
MG %
UG %
selenium
UG %
MG %
zinc
MG %
G Water G
G Starch G
G Alcohol G


FAQ

Does watermelon or onion contain more calories in 100 grams?
Watermelon and onion contain similar amounts of calories - watermelon has 30 calories in 100g and onion has 40 calories.

Does watermelon or onion have more carbohydrates?
By weight, watermelon and onion contain similar amounts of carbs - watermelon has 7.6g of carbs for 100g and onion has 9.3g of carbohydrates.