Watermelon
Nutrition Information
| Nutrient / Component | Per 100 g | Per 1 Cup Diced (152 g) |
|---|---|---|
| Energy (Calories) | 30 kcal | 46 kcal |
| Water | 91.4 g | 139.0 g |
| Protein | 0.61 g | 0.93 g |
| Total Fat | 0.15 g | 0.23 g |
| Total Carbohydrates | 7.55 g | 11.48 g |
| Dietary Fiber | 0.4 g | 0.61 g |
| Total Sugars | 6.20 g | 9.42 g |
| — Fructose | 3.36 g | 5.11 g |
| — Glucose | 1.58 g | 2.40 g |
| — Sucrose | 1.21 g | 1.84 g |
| Potassium | 112 mg | 170.2 mg |
| Phosphorus | 11 mg | 16.7 mg |
| Magnesium | 10 mg | 15.2 mg |
| Calcium | 7 mg | 10.6 mg |
| Sodium | 1 mg | 1.5 mg |
| Iron | 0.24 mg | 0.36 mg |
| Vitamin C | 8.1 mg | 12.3 mg |
| Vitamin A (RAE) | 28 µg | 42.6 µg |
| Lycopene | 4,532 µg | 6,889 µg |
| Choline | 4.1 mg | 6.2 mg |
Description
Watermelon (Citrullus lanatus) is one of the most hydrating, refreshing, and low-calorie fruits globally, making it a cornerstone food for summer hydration, weight loss, and exercise recovery regimens. When examining watermelon nutritional value per 100g, raw fresh watermelon delivers just 30 calories, 7.6 grams of total carbohydrates, and nearly 92% water content, categorizing it as a prime high-volume, low-energy-density whole food. A standard dietary serving—regularly logged as 1 cup of diced watermelon (approx. 152 grams)—contains roughly 46 calories and 11.5 grams of total carbohydrates, providing substantial satiety and fluid volume for minimal caloric cost.
Carbohydrate Composition, Glycemic Load & Natural Sugars
The energy in watermelon comes almost entirely from natural, fast-digesting simple sugars. A 1-cup diced serving supplies approximately 9.4 grams of natural sugars—primarily dominated by fructose, along with balanced portions of glucose and small fractions of sucrose—paired with 0.6 grams of dietary fiber. While watermelon has a relatively high glycemic index (GI ~72 to 80) due to rapid carbohydrate absorption, its glycemic load (GL) per typical serving is very low (~4 to 5). Because the fruit is over 91% water, the absolute concentration of carbohydrates per standard portion is low, meaning moderate servings will not cause dramatic blood sugar spikes in healthy individuals.
Lycopene & L-Citrulline: Functional Super-Nutrients
Beyond basic macronutrients, watermelon stands out in clinical nutrition for its exceptional concentration of two functional bioactive compounds:
Lycopene Concentration: Watermelon is one of the richest whole-food sources of lycopene—delivering around 6,890 µg to 6,980 µg per cup, exceeding even raw red tomatoes. Lycopene is a potent lipid-soluble carotenoid antioxidant that neutralizes singlet oxygen radicals, helps protect skin from photo-oxidative UV stress, and supports cardiovascular and prostate health.
L-Citrulline & Nitric Oxide Production: Watermelon (especially the white inner rind flesh) is the most abundant natural dietary source of the non-essential amino acid L-citrulline. In the body, citrulline converts to L-arginine, a direct precursor to nitric oxide ($NO$) synthesis. Nitric oxide relaxes vascular endothelial smooth muscle, promoting vasodilation, improving peripheral blood flow, lowering arterial blood pressure, and accelerating post-workout muscle soreness recovery.
Hydration Electrolytes & Essential Micronutrients
Watermelon serves as a natural isotonic whole food that helps restore cellular fluid balance:
Potassium: Delivering 112 mg per 100g (and approximately 170 mg per 1-cup serving), potassium aids intracellular osmotic balance, counteracts excess dietary sodium, and prevents muscle cramping during warm conditions or workouts.
Vitamin C (Ascorbic Acid): A single cup provides roughly 12.3 mg to 12.5 mg of Vitamin C (about 14% of the daily value), bolstering immune resilience and supporting endogenous collagen synthesis.
Vitamin A & Beta-Carotene: Supplying roughly 43 µg RAE of Vitamin A per cup, watermelon aids eye tissue maintenance, mucosal integrity, and visual pigment generation.
