Watermelon vs. Pineapple — Health Impact and Nutrition Comparison

Calories

Both are low in calories; however, pineapple contains more calories than watermelon. It has 50 calories per 100 g, while watermelon has 30 per 100 g. One average serving of watermelon contains 84 calories, while one serving of pineapple provides 83 calories.

Protein

Both fruits are very low in protein. A 100 g portion of pineapple and watermelon contains 0.54 g and 0.6 g of protein, respectively. One serving of pineapple contains 0.9 g of protein. Pineapple is richer in essential amino acids such as lysine, leucine, and valine but lower in tryptophan. Regarding protein quality, watermelon contains tryptophan, threonine, and lysine in equal amounts and at the highest concentrations.

Fats

Both contain an insignificant amount of fat: 0.12 g and 0.15 g in 100 g of pineapple and watermelon, respectively. They contain no useful trans fats and little saturated fat, and neither contains cholesterol.

Fat Type Comparison

Fat type breakdown side-by-side comparison

Watermelon

2

Saturated Fat: Sat. Fat 0.016 g

Monounsaturated Fat: Mono. Fat 0.037 g

Polyunsaturated fat: Poly. Fat 0.05 g

Pineapple

1

Saturated Fat: Sat. Fat 0.009 g

Monounsaturated Fat: Mono. Fat 0.013 g

Polyunsaturated fat: Poly. Fat 0.04 g

Contains more Mono. FatMonounsaturated Fat	+184.6%
Contains more Poly. FatPolyunsaturated fat	+25%

Contains less Sat. FatSaturated Fat

-43.8%

Carbohydrates

Pineapple is higher in carbohydrates than watermelon, containing around 13.1 g of carbohydrates compared to 7.5 g in watermelon. It is richer in both net carbohydrates and fiber content. One serving of pineapple and watermelon contains 21.6 g and 21.1 g of carbohydrates, respectively.

Of the 13.1 g of pineapple's carbs, 11.7 g (89%) are net carbs and 1.4 g (11%) is dietary fiber. Of the 7.5 g of watermelon carbs, 7.1 g are net carbs, and 0.4 g is dietary fiber.

The sugars found in pineapple and watermelon are sucrose, glucose, and fructose, each in a balanced proportion that complements the nutritional value of these fruits.

Carbohydrate type comparison

Carbohydrate type breakdown side-by-side comparison

Watermelon

2

Starch: 0 g

Sucrose: 1.21 g

Glucose: 1.58 g

Fructose: 3.36 g

Lactose: 0 g

Maltose: 0.06 g

Galactose: 0 g

Pineapple

2

Starch: 0 g

Sucrose: 5.99 g

Glucose: 1.73 g

Fructose: 2.12 g

Lactose: 0 g

Maltose: 0 g

Galactose: 0 g

Contains more FructoseFructose	+58.5%
Contains more MaltoseMaltose	+∞%

Contains more SucroseSucrose

+395%

~equal in Starch ~0g

~equal in Glucose ~1.73g

~equal in Lactose ~0g

~equal in Galactose ~0g

Vitamins

Pineapple contains seven times more vitamin K, six times more vitamin C and folate, and twice as much vitamin B6 and vitamin B3 (niacin) than watermelon. Vitamin B2 (riboflavin), vitamin B1 (thiamin), and choline are also higher in pineapple.

On the other hand, watermelon has ten times more vitamin A and 2.5 times more vitamin E. Both contain no vitamin D or vitamin B12 and equal amounts of vitamin B5.

Vitamin Comparison

Vitamin comparison score is based on the number of vitamins by which one or the other food is richer. The "coverage" charts below show how much of the daily needs can be covered by 300 grams of the food.

Watermelon

2

Pineapple

8

Contains more Vitamin AVitamin A	+881%
Contains more Vitamin EVitamin E	+150%

Contains more Vitamin CVitamin C	+490.1%
Contains more Vitamin B1Vitamin B1	+139.4%
Contains more Vitamin B2Vitamin B2	+52.4%
Contains more Vitamin B3Vitamin B3	+180.9%
Contains more Vitamin B6Vitamin B6	+148.9%
Contains more Vitamin KVitamin K	+600%
Contains more FolateFolate	+500%
Contains more CholineCholine	+34.1%

~equal in Vitamin D ~0µg

~equal in Vitamin B5 ~0.213mg

~equal in Vitamin B12 ~0µg

Minerals

Pineapple has 24 times more manganese, two times more calcium, and copper than watermelon. Watermelon contains more phosphorus and selenium.

Both have an equal amount of iron, magnesium, zinc, potassium, and sodium.

Mineral Comparison

Mineral comparison score is based on the number of minerals by which one or the other food is richer. The "coverage" charts below show how much of the daily needs can be covered by 300 grams of the food.

Watermelon

2

Pineapple

6

Contains more PhosphorusPhosphorus	+37.5%
Contains more SeleniumSelenium	+300%

Contains more MagnesiumMagnesium	+20%
Contains more CalciumCalcium	+85.7%
Contains more IronIron	+20.8%
Contains more CopperCopper	+161.9%
Contains more ZincZinc	+20%
Contains more ManganeseManganese	+2339.5%

~equal in Potassium ~109mg

~equal in Sodium ~1mg

Oxalates

The oxalate content of pineapple is 5 mg per 100 grams, and that of watermelon is 0 mg per 100 mg. Both are low in oxalates.

Glycemic Index

Pineapple's glycemic index (GI) is 66, considered medium, while the glycemic index of watermelon is 76, considered high. This indicates that compared to pineapple, watermelon can increase blood sugar levels more quickly. 

Glycemic Load

Both pineapple and watermelon have medium glycemic loads, with pineapple having a glycemic load of 13 and watermelon having a 15. This indicates that both fruits can moderately impact blood sugar levels when consumed in typical serving sizes.

Acidity

Both pineapple and watermelon have alkaline properties based on their Potential Renal Acid Load (PRAL) values. Pineapple has a PRAL of -2.2, indicating it is slightly more alkaline than watermelon, which has a PRAL of -2.

Cardiovascular Health

Pineapple, with its antioxidants like phenolic compounds and flavonoids, is a powerful ally in the fight against heart disease, chronic inflammation, diabetes, and some malignancies. Pineapple's 'bound' antioxidants provide long-lasting protection like a fortress. Watermelon, on the other hand, is a heart health warrior with its high lycopene content that battles cholesterol and blood pressure. Furthermore, it contains citrulline, an amino acid that relaxes blood vessels and reduces blood pressure. Filled with vital vitamins and minerals, including magnesium, potassium, and vitamins A, B6, and C, watermelon is a powerhouse for cardiovascular and general health.

  Digestive Health

Pineapples include bromelain, a group of digestive enzymes that helps break down protein molecules, facilitating easier absorption in the small intestine (5). This enzyme is particularly beneficial for individuals with pancreatic insufficiency and is also used commercially as a meat tenderizer because of its capacity to break down tough meat proteins (6, 7). Also, pineapple is an excellent source of fiber, which further aids digestion (8). On the other hand, watermelon is rich in water and contains a small amount of fiber, both essential for maintaining healthy digestion (9).  The high water content in watermelon helps efficiently move waste through the digestive tract, while the fiber helps keep bowel movements regular. 

Cancer

Pineapple is high in bromelain, an enzyme that has shown potential in reducing cancer risk by minimizing oxidative stress and inflammation. Some studies have found that bromelain can suppress the development of cancer cells and induce their death, particularly in breast cancer (10, 11, 12). However, more human research is needed to confirm these effects. Watermelon, on the other hand, contains lycopene and cucurbitacin E, which have been associated with possible anticancer effects. Lycopene may lower the risk of prostate and colorectal cancers by reducing insulin-like growth factor (IGF) levels (13, 14, 15). This hormone promotes cell division, while cucurbitacin E may inhibit tumor growth by destroying and removing cancer cells (16). 

Skin and Hair Health

It is crucial to nourish your skin and hair with vitamins A and C. The primary function of vitamin A is to help create and repair skin cells. Collagen keeps your skin and hair supple and strong. Vitamin C may help produce collagen. A lack of Vitamin A will cause your skin to appear dry and flaky (17, 18, 19). Pineapple and watermelon are both picked with high levels of these vitamins. Watermelon also contains lycopene and beta-carotene, which prevent sunburn (20, 21).