If asked to guess the weights of others, most obese people get it wrong compared to people of normal weight, a new study shows.

Researchers at the Columbia University Medical Center say that overweight people also fail to see their abnormal weight increase and risk tolerance to obesity. This tendency is seen among mothers of obese children and even children who have overweight parents

"The failure to recognize abnormal weight occurs more often among overweight or obese mothers and children," lead author Tracy Paul from the Weill-Cornell Medical College said in a press statement.

She further explained that children of obese mothers mostly misjudge their weight. This shows that tolerance to obesity is prevalent among children exposed to obese parents. The team said that most parents of obese children do not try to prevent their children from becoming overweight only because they fail to recognize abnormal weight.

According to the U.S. Food Research and Action Center, at least two-thirds of adults in America are overweight or obese. Around a quarter of children aged between 2 and 5 and one-third of school-age children (including adolescents) are overweight or obese. Nearly 30 percent of low-income preschoolers are overweight or obese. 

For the current study, researchers interviewed 253 mothers and their children. The participants were asked about their perceptions of what healthy and ideal body sizes are.

The findings revealed that 71.4 percent of obese adults and 35.1 percent of overweight adults underestimated size as opposed to 8.6 percent of people of normal weight.

Among overweight and obese children, 86.3 percent and 62.3 percent respectively thought they weighed less than they do. This was the case among just 14.9 percent of children with normal weight.

Moreover, mothers of children who were overweight had scored poorly in estimating the sizes of their children. Researchers found that 80 percent of them underestimated the weight of their children, compared to 7.1 percent of mothers with normal weight children and 23.1 percent of mothers with obese kids.

"This is worrying, as flawed weight perception impedes one's ability to recognise obesity and its risks as a personal health issue," Paul said.

The study was published in the Journal of General Internal Medicine.