Mini packets of crisps, sweets and biscuits, are becoming increasing popular among children and those keen to watch their weight.
However, new research suggests that the size of the packaging could actually be counterproductive.
Scientists gave different sized bags of potato crisps, divided into small and large packets, to 140 students recruited for what they were told was an experiment on advertising and television.
Each of the volunteers was given either two 200-gram bags of crisps or nine 45-gram bags, to munch as they watched TV. The group was asked a series of questions and were weighed in front of a mirror to trigger a diet "mindset"
The findings, published today in New Scientist magazine, show that students who were worried about their weight ate twice as many crisps if they came in small packets rather than large packets.
The group were also more likely to open the crisps and start eating them if they came in a smaller bags.
Almost 60 per cent of those with small bags opened them and started eating, compared with only a quarter of those who were assigned large bags.
Smaller bags did not appear to curb the appetite of students without weight concerns either.
Those students ate the same amount of crisps from small as large bags.
However, those with the smaller packets were again more likely to open them.
Three quarters of the group with small bags opened theirs while only half of those with large bags started eating the crisps.
