Warning women that eating chocolate can make them fat may actually drive some to eat more, research from the University of Western Australia (UWA) shows.
The joint study with the University of Strathclyde in Scotland found low restraint eaters - those not on a diet - showed a strong impulse to eat chocolate when presented with negative messaging, including warnings that chocolate could lead to obesity.
Women on a diet were also prone to rebel against attempts to scare them off chocolate, particularly by ads featuring thin models.
Researchers found dieters shown ads featuring thin models displayed an increased desire to eat chocolate coupled with greater feelings of wanting to avoid consumption, or indulged in higher consumption - and ultimately felt more guilt.
Lead author Professor Kevin Durkin said the reaction of a warning having a contrary effect was known as "reactance".