Children who watch adverts for junk food on television become hungrier and crave meals that are unhealthily for them, researchers have revealed.
Children aged six to 13 who were shown commercials for high fat and high carbohydrate foods were found more likely to pick meals that were bad for them.
The effect was especially pronounced in those who usually watched more than 21 hours of television per week - with these children in particular wanting burgers and fries instead of a salad.
The team from the University of Liverpool showed 281 children 10 adverts for junk food and asked them to fill out a questionnaire about their eating preferences.
After exposure to the junk food adverts there was a 'significant' increase in the number who chose branded and non-branded foods that were bad for them.
"The unhealthy options we gave them after the adverts were not the same as those which were featured in the adverts. This suggests that children are encouraged to eat bad food in general, which is worse," the Daily Mail quoted lead researcher Dr Emma Boyland as saying.
The findings have prompted scientists to call for a 9pm 'watershed' on junk food adverts to make sure their exposure to children is minimal.