'Chocolate is four times more exciting than kissing'

But it is no comparison to the sensation of chocolate melting on the tongue, a study has discovered.

Young volunteers' hearts and heads were hooked up to electrodes and asked to taste pieces of dark chocolate before kissing their partners.

The deflating discovery was that chocolate provides a buzz lasting up to four times as long as embracing the special person in our lives.

The findings would be supported by former Baywatch babe Pamela Anderson, who recently said chocolate was better than sex.

But neurophysiologist Dr David Lewis, who led the study, said he had been taken aback.

"These results really surprised and intrigued us," he said.

"While we fully expected chocolate - especially dark chocolate - to increase heart rates due to the fact it contains some highly stimulating substances, both the length of the increase together with the powerful effects it had on the mind were something none of us had anticipated."

The volunteers, all in their 20s, took part in the experiment in an area designed to look like a place of work to create the impression of an office romance.

Each had electrodes attached to their scalps and wore heart monitors as they popped a piece of dark chocolate on their tongue and, without chewing, indicated when it started to melt.

The young lovers then had to kiss each other in the same way they would normally - while researchers in white coats and carrying clipboards "studied their monitors".

As part of the controlled experiment, measurements of heart and brain activity were also taken when there was no external stimulation of the senses.

The study revealed that, at the point chocolate melts in the mouth, all regions of the brain receive a boost far more intense and longer lasting than the excitement produced by kissing.

The chunks of chocolate also made the heart beat faster.

For some of the 12 volunteers, the number of beats per minute more than doubled from a resting rate of 60 to as much as 140.

Kissing also set hearts racing but the effect was shorter-lasting.

Although woman are generally considered to be bigger chocoholics than men - and bigger romantics - both sexes showed the same responses in the tests.

Only one volunteer bucked the trend - a 21-year-old man who had recently met his 24-year-old girlfriend.

Former Sussex University academic Dr Lewis, who now runs private research company The Mind Lab, said: "The results were given to the volunteers. I don't know if this couple are still together."

He added: "There is no doubt that chocolate beats kissing hands down when it comes to providing a long-lasting body and brain buzz - a buzz that, in many cases, lasted four times as long as the most passionate kiss."

But Deanne Jade, an expert in the psychology of how people relate to food, warned kissing someone in a 'non-erotic or non-personal environment' wouldn't have the same effect as embracing in a private moment.

Chocolate contains a number of substances that give 'natural highs', including phenylethylamine, which is produced by the body when people are in love, and theobromine. It also contains caffeine.

The research was conducted using a new chocolate from Cadbury called Deeply Dark which is not yet on sale.

It is made from a 60 per cent cocoa recipe similar to one used exclusively for the Royal Family since the days of Queen Victoria. Earlier this year, research revealed dieting increased women's cravings for chocolate.