Watermelon vs. Guava — Health Impact and Nutrition Comparison

Calories

With only 30 calories per 100 grams, watermelon has a substantially lower calorie content than guava, which has 68 calories per serving.

Protein

There should be minimal protein in these two plants. Each 100g of them has very little protein in it. That sum can be ignored. 

Fats

Fruits like guava and watermelon have hardly any fat.

Fat Type Comparison

Fat type breakdown side-by-side comparison

Watermelon

1

:

2

Guava

Contains less Saturated Fat -94.1%

Contains more Monounsaturated Fat +135.1%

Contains more Polyunsaturated fat +702%

Watermelon

Saturated Fat: 0.016 g

Monounsaturated Fat: 0.037 g

Polyunsaturated fat: 0.05 g

Guava

Saturated Fat: 0.272 g

Monounsaturated Fat: 0.087 g

Polyunsaturated fat: 0.401 g

Contains less Saturated Fat -94.1%

Contains more Monounsaturated Fat +135.1%

Contains more Polyunsaturated fat +702%

Vitamins

Guava is superior to watermelon for numerous essential vitamins. Vitamin A levels are more significant in guava (624 IU vs. 569 IU) and Vitamin A RAE (31 g vs. 28 g). It also has more amounts of Vitamin E (0.73mg vs. 0.05mg), Vitamin C (228.3mg vs. 8.1mg), Vitamin B1 (0.067mg vs. 0.033mg), Vitamin B2 (0.04mg vs. 0.021mg), Vitamin B3 (1.084mg vs. 0.178mg), Vitamin B5 (0.451mg vs. 0.221mg), Vitamin B6 (0.11mg vs. 0.045mg), Folate (49 g vs. 3 g), and Vitamin K (2.6µg vs. 0.1 g) compared to watermelon. 

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

0

:

10

Guava

Contains more Vitamin E +1360%

Contains more Vitamin C +2718.5%

Contains more Vitamin B1 +103%

Contains more Vitamin B2 +90.5%

Contains more Vitamin B3 +509%

Contains more Vitamin B5 +104.1%

Contains more Vitamin B6 +144.4%

Contains more Folate +1533.3%

Contains more Vitamin K +2500%

Equal in Vitamin A - 624

Watermelon

Guava

Contains more Vitamin E +1360%

Contains more Vitamin C +2718.5%

Contains more Vitamin B1 +103%

Contains more Vitamin B2 +90.5%

Contains more Vitamin B3 +509%

Contains more Vitamin B5 +104.1%

Contains more Vitamin B6 +144.4%

Contains more Folate +1533.3%

Contains more Vitamin K +2500%

Equal in Vitamin A - 624

Minerals

Guava has higher levels of calcium (18 mg vs. 7 mg), magnesium (22 mg vs. 10 mg), phosphorus (40 mg vs. 11 mg), potassium (417 mg vs. 112 mg), zinc (0.23 mg vs. 0.1 mg), and copper (0.23 mg vs. 0.042 mg) compared to watermelon. 

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

1

:

9

Guava

Contains less Sodium -50%

Contains more Calcium +157.1%

Contains more Magnesium +120%

Contains more Phosphorus +263.6%

Contains more Potassium +272.3%

Contains more Zinc +130%

Contains more Copper +447.6%

Contains more Manganese +294.7%

Contains more Selenium +50%

Equal in Iron - 0.26

Watermelon

Guava

Contains less Sodium -50%

Contains more Calcium +157.1%

Contains more Magnesium +120%

Contains more Phosphorus +263.6%

Contains more Potassium +272.3%

Contains more Zinc +130%

Contains more Copper +447.6%

Contains more Manganese +294.7%

Contains more Selenium +50%

Equal in Iron - 0.26

Glycemic Index

The glycemic index of guava is 31, indicating that it has a relatively minor impact on blood sugar levels when consumed. In contrast, the GI of watermelon is 76, signifying a more substantial impact on blood sugar levels after consumption. 

Glycemic Load

Guava has a low glycemic load (GL) of 2, and watermelon has a higher glycemic load of 15.

Acidity

Based on the Potential Renal Acid Load (PRAL) values, both guava and watermelon have alkaline profiles, indicating they are alkaline-forming foods. On the other hand, Guava has a somewhat higher alkaline PRAL value of -6.8, whereas watermelon has a PRAL value of -2, which is still alkaline but not as much as guava.

Cardiovascular Health

Through its antioxidants, vitamins, and high vitamin C content, guava lowers the risk of cardiovascular disease, atherosclerosis, hypertension, diabetes, obesity, and metabolic syndrome by reducing oxidative damage, lowering cholesterol and triglyceride levels, increasing cardioprotective HDL levels, and lowering cholesterol and triglyceride levels (1, 2, 3).  Lycopene, citrulline, and amino acids found in watermelon, on the other hand, may decrease cholesterol and blood pressure and lessen arterial wall stiffness (4, 5). Due to its diuretic properties, it may decrease blood pressure. Although research in rats indicates improved lipid profiles and decreased inflammation, further human trials are required to validate these cardiovascular advantages (6).  

Diabetes

Guava intake has been linked to reduced fasting blood glucose levels and better insulin and blood sugar management, which lowers the risk of type 2 diabetes (7).  Additionally, guava consumption may reduce cholesterol and blood sugar levels, which may lessen the risk of obesity (8).  Contrarily, there is less direct evidence linking watermelon intake to the control of diabetes. Lycopene, an antioxidant with significant anti-inflammatory properties found in abundant watermelon, may help prevent chronic illnesses, but further study is required (9).  By lowering the activity of enzymes and transporters that control blood sugar, watermelon also has anti-diabetic effects that help avoid blood sugar increases (10). 

Cancer

The data for the possible anticancer effects of guava and watermelon comes mostly from test-tube and animal studies; thus, further human study is required. Guava has been shown to have the potential to suppress the proliferation of cancer cells, notably in metastatic prostate cancer cases, especially when its leaves and aqueous extract are used (11). It is a potential option for cancer therapy due to its high polyphenol and flavonoid content. The powerful antioxidant lycopene in watermelon has also been linked to anti-cancer properties (12). Lycopene may impact insulin-like growth factors associated with cancer, lower oxidative stress, and fight free radicals, lowering the chance of developing cancer. 

Allergy 

Although uncommon, allergic responses to watermelon can cause symptoms that resemble those of food allergies, such as hives, itchy or tingly lips, tongue or throat, coughing, and gastrointestinal discomfort (such as stomach ache or cramping) (13). The medical literature, however, hardly ever mentions guava allergies. According to some studies, targeted exclusion diets may help reduce seasonal exacerbations, which shows that children who experience seasonal asthma episodes may be more susceptible to hypersensitivity to specific foods, including guava (14). Guava tea leaves, which might have allergenic ingredients, including pollen and latex, have also been connected to allergic skin dermatitis (15).  Allergies to either fruit are uncommon; however, allergies to watermelon are significantly more common.

Immune System

Both watermelon and guava have health advantages, primarily due to the vitamin C they contain, which works as an antioxidant and immune system builder (16).  Even though these effects might not always be related to eating the whole fruit, guava extracts have demonstrated promise in reducing the incidence of diabetic nephropathy and easing menstrual discomfort (17, 18).  Watermelon has shown the ability to lessen oxidative stress and inflammation since it contains anti-inflammatory antioxidants and vitamin C. The vitamin A in watermelon is also noteworthy since it is necessary for skin restoration after injury (19).