Watching a skinny model tuck into a bar of chocolate is more likely to put us off buying it, a new study has revealed.

Slim, seductive models are frequently used in chocolate advertising - think of the Cadbury"s Flake advertisements - but they may be stopping women from indulging in sweet treats.

Researchers at the University of Strathclyde in Glasgow said if an ad featured larger women it meant we had less likelihood of worrying about eating chocolate.

They asked 84 women between the ages of 17-63 about their chocolate-eating habits and if they had guilty feelings after consuming it.

They divided the group into three and asked one group to look at images of slim models promoting chocolate, showed another group pictures of larger women eating chocolate and did not show the last group any images.

Women who looked at the slim models were less likely to want to eat chocolate, while those who looked at the larger models felt less worried about eating it.

The researchers wrote in the Appetite journal: "Chocolate advertisements often include models exemplifying an idealised female form. Presumably, advertisers seek to convey the implicit message that eating this sweet is somehow conducive to enhanced physical attractiveness."

"Our findings indicate the use of thin models can increase craving but also increases avoidance and guilt."