Fat-free frenzy.

Imagine scarfing down a bowl of chips - without consuming an ounce of fat. To the delight of some snackers, that dream may soon Come true. Procter & Gamble recently got the go-ahead from the U.S. Food and Drug Administration (FDA) to sell snacks containing olestra, a new zero-calorie fat substitute.

Unlike ordinary fat molecules, olestra molecules are too big for digestive enzymes (proteins in your intestines) to break down. Result: Instead of being absorbed into the bloodstream, olestra passes right through your body.

But not everyone's thrilled to see olestra hit the shelves - or your stomach. Some scientists worry that olestra may grab hold of other nutrients and carry them out of the body before they can be absorbed. For instance, olestra is known to adhere to carotenoids, nutrients found in carrots and other veggies, which may reduce the risks of cancer, heart disease, and other illnesses.

In addition, studies show that eating olestra-laden snacks can lead to digestive problem like gas, bloating, and diarrhea. "Olestra is an unfit substance for human consumption," says Michael Jacobson of the Center for Science in the Public Interest.

But P & G researchers maintain that they've tested olestra for nearly three decades, including tests on kids. "This research shows olestra can be safely used in foods," says Penny Kris-Etherton, a nutritionist who reviewed the studies.

Will olestra chips make the grade or will they fall flat? Stay tuned as science munches on and the taste tests begin.