Glycemic index key to many new diets: what patients are reading.(News)

Diet books are perennially popular, even though the heroes and villains of the food world seem to change places every few years.

Meats, eggs, and dairy products were vilified for years as the culprits in this country's growing obesity epidemic. But the current bestsellers maintain that carbohydrates--some of which are said to cause high insulin levels--are among the true culprits behind Americans' expanding waistlines.

"Glycemic index" now ranks as the buzz phrase of choice among those looking for the magic bullet that will help shed those unwanted pounds.

Four tomes that recently made the New York Times bestseller list tout the virtues of foods with a low glycemic index (GI), which is the degree to which a particular food boosts blood glucose relative to a reference food, usually white bread or glucose.

In theory, the rapid rise in blood sugar produced by foods with a higher GI triggers an outpouring of insulin that, in turn, promotes both fat storage and weight gain.

Here's a brief look at each of the plans:

* "The New Sugar Busters!" (H. Leighton Steward; Morrison C. Bethea, M.D.; Sam S. Andrews, M.D.; and Luis A. Balart, M.D. New York: Ballantine Books, 2003).The key to this diet is modulating insulin secretion by eating foods with a low-to-moderate GI in an effort to prevent the release of insulin provoked by simple and refined carbohydrates, most of which have a high GI.