A new pill developed by Italian scientists expands in the stomach and make dieters feel full.
The effect is apparently similar to eating a bowl of spaghetti and the pill can stall hunger pangs for quite a few hours.
The pill is made from a hydrogel, which the team developed when trying to make more absorbent nappy linings, and has been tested on 20 people.
The researchers believe it may help in the battle against obesity but experts warn that larger trials are needed in order to test the drugs' safety.
Professor Luigi Ambrosio, lead researcher on the study at Italy's National Research Council, realised when they developed the hydrogel that it could have the same effect as gastric banding, a surgical procedure that reduces the size of the stomach and limits what can be eaten.
The pill was tested on one of the research team who took it at 11am and still felt full at six in the evening.
According to Professor Ambrosio, the tiny pill is powdery when dry but when swallowed with a glass of water the pill expands into a ball of jelly when it hits the stomach.
It is made from an organic compound called cellulose and can be flushed out by the body; it is currently being tested in a further 90 overweight volunteers who will be monitored to see how much weight they lose and if there are any adverse effects.
Professor Ambrosio says the pill should be taken about 30 minutes to one hour before each meal and passes through the digestive system within five to six hours.
People are still able to eat a small meal after taking it.
The results of the trial should be available in October and the product will be launched in May 2008.
Experts say the idea is reasonable but would need to be given with the appropriate nutritional advice, as a person cannot live on such tablets.