People eat more when they are glued to the television, and the more entertaining the programme, the more they eat, according to research presented on Saturday.

"It seems that distracted brains do not notice what the mouth is doing," said Dr Alan Hirsch, neurological director of the Smell and Taste Treatment and Research Foundation in Chicago.

Hirsch explored the impact of smell, taste and eating behaviours while watching TV by measuring potato chip consumption. Forty-five volunteers ate as many chips as they wanted during five-minute intervals over three-week periods while they watched monologues by late-night talk show hosts David Letterman and Jay Leno. They also were given chips to eat when the television was off.

Hirsch found people ate an average of 44% more chips while watching Letterman and 42% more while viewing Leno, than when they did not watch TV "If you can concentrate on how the food tastes you'll eat less because you'll feel full faster," Hirsch said.