Humans are subconsciously influenced by the weight of those around them, which could lead to 'spiral of obesity', according to University of Warwick researchers.
"Human beings compare themselves among their localised peer group even if they are not conscious of it," said Professor Andrew Oswald at the University, involved in the research.
"If fatness levels increase and 'we all start copying each other' we will end up with quite serious health problems', he stressed.
Men do not worry about being overweight as long as plenty of men around them were also overweight, said the study, which will be presented at the National Bureau of Economic Research conference in Cambridge, Massachusetts in the US.
According to the research, whether someone is satisfied with their own weight depends on how they compare themselves to those around them and people with a degree or high education or qualification are particularly hard on themselves.
The researchers collected and analysed data from 27,000 European adults across 29 countries and found less than a third of men thought that they were overweight, the Daily Telegraph Newspaper said.
According to the British daily, the study found that for women whether they are happy with their own weight depended crucially upon not just their own absolute body mass index but also upon their body mass index relative to other women of exactly the same age in their country.
