Canteloupe
Why: One-quarter of a melon (about 15 cantaloupe balls) has only 70 calories or so, and there is nothing like a sweet piece of cantaloupe on a hot summer day.

Health Perks: Cantaloupe is low in calories, very low in sodium and virtually fat free. It’s also high in vitamins A and C and a good source of vitamins B6, B3 (niacin) and folate. Cantaloupes are high in the antioxidant beta carotene and in potassium, which is necessary for muscle contractions (including your heartbeat), transmission of nerve impulses and the delicate balance of fluids and electrolytes. Diets rich in potassium are known to lower blood pressure.

Nutrition: Serving size: 1/4 of a large melon (about 6 1/2" in diameter), calories 69, total fat 0.4g, cholesterol 0mg, sodium 33mg, total carbohydrate 16.6g, dietary fiber 1.8g, sugars 16g, protein 1.7g.

Seek Out: Fragrant, symmetrical melons that are heavy for their size, with a yellow or cream undertone and no visible bruises. The stem or blossom end should give to gentle pressure and smell sweet, says Green. "Another indicator with cantaloupes is the stem -- if it still has one and it won't come off easily, chances are it's not ready to eat," says Parker. Additionally, the netting or veining on the exterior of the melon should be substantial, coarse and corky. Finally, the skin color between the netting should have changed from green to yellowish-buff, yellowish-gray or pale yellow.

Avoid: According to Green, over-ripe cantaloupes have "lumps or soft spots." Small bruises are OK, but avoid the ones with large bruises. She also suggests avoiding rock-hard or lopsided melons. Also, watch out for mold growth, which can indicate decay.

Storage: Uncut melons can be stored at room temperature for up to a week. Refrigerate cut melon in an airtight container for up to five days.

Interesting: The cantaloupes we eat are actually called muskmelons.

CHARLES STUART PLATKIN is a nutrition and public health advocate, author of The Diet Detective's Count Down (Simon & Schuster, 2007) and founder of DietDetective.com, the health and fitness network.