Do you see the man in the photo above as overweight, or just big or burly? Plus-size clothing lines and other efforts to reduce the stigma of having a larger body — as well as the sheer number of people who are overweight — are having unintentional health consequences.

As larger sizes become more common, they shift the mental “yardstick” by which people gauge their size, leading them to underestimate their weight and increasing their risk of developing obesity-related diseases. The man in the photo is definitely overweight and perhaps obese. He may have diabetes, high blood pressure or be heading for heart problems.

Weight misperception is also having a negative effect on efforts to fight obesity, according to a study from the University of East Anglia that used data on the demographic and socioeconomic characteristics of nearly 24,000 people from the annual Health Survey for England.

Men were twice as likely to underestimate their weight as women.

Men, people with lower levels of education and income, and members of minority ethnic groups were more likely to underestimate their weight. In general, those who underestimated their weight were 85 percent less likely to attempt weight loss compared to people who correctly identified their weight status. Only minority group members were likely to try to lose weight.

The number of people who did not have an accurate idea of how overweight they were increased from 1997 to 2015 with men being twice as likely to underestimate their weight as women.

“The causes of socioeconomic inequalities in obesity are complex. Not only does access to health care services matter, but socioeconomic determinants related to living and working conditions and health literacy also substantially influence health and health behaviors,” explained study author, Raya Muttarak, in a statement. Public health programs are needed to identify the types of people who are prone to underestimate their weight, she believes, so that obesity prevention programs can be targeted and made more effective. And the fact that so many of us don't have a clear idea about how much we actually weigh suggests that programs to encourage a healthy weight have more work to do.

The high cost of healthy foods like fresh fruits and vegetables, compared to processed, high calorie foods, is another area that Muttarak sees as needing to be addressed. Making healthy foods more cost-effective, or even cheaper, would help motivate those trying to lose weight, as well as improving their diets.

It's easy to get an accurate picture of your weight: Put your height and weight into an online body mass index (BMI) calculator and click, Calculate. If your BMI is greater than 25, you should begin watching your diet more closely and increasing your physical activity.

The study was published in Obesity.