MILAN -- Italian scientists are testing a new diet pill that turns into a clear, gelatinous blob the size of a tennis ball that may help shrink waistlines by giving dieters a sense of satiety.

The pill, currently undergoing clinical trials at Rome's Policlinico Gemelli hospital, would be downed with two glasses of water at the first sign of a stomach rumble.

"The effect is like eating a nice plate of pasta," said Luigi Ambrosio, lead researcher on the project at the National Research Council's Institute for Composite and Biomedical Materials in Naples. "If you sit down for a meal with a stomach that already feels full, you'll end up eating less."

The unnamed pill is made from a cellulose compound of hydrogel, a material that's powdery when dry but plumps up to a cousin of Jell-O when wet. The gel can soak up to 1,000 times its weight. A gram in capsule form quickly balloons from the size of a spit wad to a ball that holds nearly a liter of liquid.