An oversupply of food is the reason for burgeoning obesity rather than inactive lifestyles - a new study suggests. File Photo: Finbarr O'Reilly

London - It will be little consolation to any woman who has stood in a changing room fretting about whether her bottom looks big – and any man who has desperately tried to convince her that it doesn’t.

We’re all fatter than we think we are, a study claims, and women are most likely to be guilty of underestimating their size.

It seems the average woman is actually 5lb (about 2.2kg) heavier than she believes she is – and those in their late 30s are the most optimistic, convinced they weigh half a stone less than they really do.

Men, meanwhile, underestimate their weight by a more modest 3lb (1.3kg), the poll of 9,000 adults found. Psychologists say it is all down to misguided optimism, with both men and women trying to convince themselves that they are not that far from the size they’d like to be.

Andrina McCormack, a charted psychologist in Dundee, Scotland, said: “What is probably happening is that there is so much social pressure to be slim that everyone wants to be thinner.

“So a woman may weigh 150lb (68kg), but she thinks that if she puts on a nice black dress and screws her eyes up she is closer to 140lb (63kg). It’s wishful thinking.”

And it seems this wishful thinking extends to how we look at our children, too. The report found that nearly half of parents whose child was obese were convinced they were “about the right weight”.

The findings come from the Government’s annual health survey, which surveys some 8,600 adults and 2,000 children. As part of the study they were asked how much they thought they weighed before being put on the scales.

Tim Straughan of the Health and Social Care Information Centre, which compiled the data, said: “This survey gives a brand new insight into how the average adult in England has a different idea of their weight compared to what the scales actually show.

“Women appear to misjudge their weight more than men - with women in their late 30s in particular underestimating their weight by nearly 8lb.”

Nearly two-thirds of adults are overweight and one in four is obese, according to NHS data. A fifth of children are obese by the time they leave primary school, with another 15 percent being overweight. - Daily Mail