A new study appears to confirm the idea that people are increasingly unable to recognise overweight in others.

US researchers questioned over 250 mothers and their children about their perceptions of body size. All were asked what they considered to be a healthy and ideal body size.

The study found that at least seven in 10 obese adults and one in three overweight adults underestimated size, compared to less than one in 10 people of normal weight. In other words, they failed to recognise if someone was an abnormal weight.

Meanwhile, 86% of overweight children and 62% of obese children thought they weighed less than they actually did, compared to 14% of normal weight children.

The study noted that the perceptions of mothers was particularly poor. Some 80% of them underestimated their child's weight compared to 7% of normal weight mothers, including almost one in four mothers with obese children.

This appeared to work both ways, with most children of obese mothers unable to classify their mum's size correctly.

"The failure to recognise abnormal weight occurs more often among overweight or obese mothers and children. Children of obese mothers often also underestimate adult size, suggesting that tolerance of being overweight is common among children exposed to obese parents. This is worrying, as flawed weight perception impedes one's ability to recognise obesity and its risks as a personal health issue," the researchers commented.

They added that obesity programmes should take account of the fact that family members may have an inaccurate view of weight.

An Irish study published in 2012 also found that parents were slow to recognise that their children might have a weight problem, with some viewing their overweight children as being of normal weight. (See more here)

Details of these latest findings from the US are published in the Journal of Internal Medicine.