The New GI Tracts

For preventing heart disease, diets that control insulin are all the buzz

It’s hard to meander down the health-and-nutrition aisles of book megastores without encountering displays for competing diet guides. The books target different parts of the population—people struggling with obesity, lack of pep, or various diseases. Recently, there’s been an explosion of volumes for a condition that some authors claim affects one-tenth to one-third of people in the United States.