Elsewhere in the world, the fall harvest means a wave of seasonal fruits and vegetables — and they're appearing in local supermarkets. Here's what's so good about them.

BUTTERNUT SQUASH

Why: Butternut squash soup. Isn't that a good enough reason? It is thick, satisfying and simple to make. Just seed and cube the squash, add onion, garlic and water or fat-free chicken broth, cook until the squash is soft and puree in the blender. Tasty! Unlike zucchini, which is a summer squash, winter squash (e.g., butternut squash) is almost always served cooked and seasoned with spices such as cinnamon, cumin or curry. Some say that the bell-shaped squash is a sweeter, nuttier pumpkin.

Health perks: Butternut squash is an excellent source of vitamin A, which is said to have antioxidant properties. It's low in calories, and 1 cup provides 3 grams of fiber, half your daily requirement for vitamin C, and a good dose of potassium, manganese, thiamin, vitamin B6, niacin and calcium.

Nutrition: 1 cup (140g) has 63 calories, 0.14 g fat, 16.4 g carbs, 3 g fiber, 1.5 g protein.

Seek out: The squash should feel heavy for its size and have deep tan skin. It should have a smooth, dry, firm, dull rind and a firm, rounded, dry stem.

Avoid: Cracks, or a shiny rind, which indicates the squash was picked too early. A soft skin is a sign of decay. A missing stem lets bacteria enter the vegetable.

Storage: Whole squash can be stored three months or longer in a cool, dry place. "The moist, stringy portion inside starts to break down first, but once scraped out and discarded, the rest is fine to eat," says Aliza Green, author of "Field Guide to Produce" (Quirk Books, 2004).

Interesting: There are many varieties of winter squash, including acorn, banana, buttercup, Hubbard and spaghetti.

SWEET POTATOES

Why: Nothing says fall like sweet potatoes. They're versatile, nutritious and tasty. And you can make guiltless fries with them. Sweet potatoes either have pale yellow, dry flesh or dark orange, moist flesh. The orange variety is thicker and sweeter.

Health perks: One potato provides 370 percent of your daily needs for vitamin A as well as 8 percent of your magnesium and 13 percent of your potassium. It's also a good source of vitamins C, B6, thiamin, riboflavin and niacin, as well as calcium and iron.

Nutrition: One potato (5 inches long, 130 g) has 112 calories, 0.07 g fat, 26 g carbs, 4 g fiber, 2 g protein.

Seek out: Firm, smooth, dark-colored skin.

Avoid: Wrinkles, bruises, sprouts, stickiness or other signs of decay.

Storage: They keep for up to a month in a dry, cool place (55 to 60 degrees) or about a week at room temperature. Don't store them in the fridge, and wash when ready to cook.

Interesting: Nutritionally, sweet potatoes beat yams. Although the two terms are used interchangeably, the sweet potato is a member of the morning glory family, while the yam is a tuber generally found only in Latin American markets.

PEARS

Why: They are the second most popular fruit in the U.S. (after the apple). They're succulent and sweet.

Health perks: A medium pear has 5.5 grams of fiber, 212 milligrams of potassium and is a good source of vitamin C.

Nutrition: One medium (178 g) has 103 calories, 0.2 g fat, 27.5 g carbs, 5.5 g fiber, 0.68 g protein.

Seek out: Slightly green, unblemished skin. Pears are harvested unripe and need to be ripened off the tree. According to the Pear Bureau Northwest, Bartlett pears change from green to yellow as they ripen. Other varieties, including Anjou, Bosc, Comice and Seckel, do not change color. Ripe pears will give a bit when pressed near the stem. "Choose pears with skin that is starting to look waxy, rather than shiny and hard," says Green.

Avoid: Bruises or cuts and dark brown colors, "and overly green or hard pears, which will be difficult to ripen," adds Green.

Storage: Put them in a paper bag to ripen for a couple of days. Then you can keep them in the fridge for a few more days. When sliced apples or pears are exposed to air, oxidation turns the flesh brown. Brush with a solution of water and lemon juice to avoid this.

Interesting: There are more than 3,000 varieties.

POMEGRANATE

Why: Haven't you heard? It's a super food. When you split it open you'll see large groupings of red seeds in a spongy white casing — the sweet-tart flavored seeds are what you eat.

Health perks: OK, maybe it can't cure every disease, as many juice distributors would have you believe. However, it is a good source of vitamin C and potassium, and a good source of fiber. Also, it's low in calories. The pomegranate is high in powerful antioxidants called polyphenols — tannins, anthocyanins, and ellagic acid. It is also high in phytosterols (plant sterols), which help lower cholesterol. The pomegranate is known for reducing the risk factors for cardiovascular diseases and some cancers.

Nutrition: One pomegranate (3 3/8 inches in diameter, 154 g) has 105 calories, 0.5 g fat, 27 g carbs, 1 g fiber, 1.5 g protein.

Seek out: Fruit with a lot of bright color in the skin. It should feel heavy for its size.

Avoid: Blemished skin.

Storage: Pomegranates keep in the fridge for about two months and at room temperature for a couple of weeks. You can freeze the seeds for a few months.

Interesting: You can blend the seeds and strain them to make your own juice. To remove the seeds: Cut the pomegranate's crown off, then cut into sections. Put the sections in a bowl of water for five minutes, then roll out the seeds with your fingers and strain out the water.

Charles Stuart Platkin is a nutrition and public-health advocate, and author of "Breaking the FAT Pattern" (Plume, 2006). Sign up for the free Diet Detective newsletter at www.dietdetective.com.