Discrimination against overweight people - particularly women - is as common as racial discrimination, according to a study by the Rudd Center for Food Policy & Obesity at Yale University.

"These results show the need to treat weight discrimination as a legitimate form of prejudice, comparable to other characteristics like race or gender that already receive legal protection," said Rebecca Puhl, research scientist and lead author.

The study documented the prevalence of self-reported weight discrimination and compared it to experiences of discrimination based on race and gender among a nationally representative sample of adults aged 25- to 74-years-old. The data was obtained from the National Survey of Midlife Development in the United States.

The study also revealed that women are twice as likely as men to report weight discrimination and that weight discrimination in the workplace and interpersonal mistreatment due to obesity is common.

The researchers found that men are not at serious risk for weight bias until their body mass index (BMI) reaches 35 or higher, while women begin experiencing a notable increase in weight discrimination risk at a BMI level of 27. BMI is the measure of body fat based on height and weight.

Co-author Tatiana Andreyava of Yale said weight discrimination is more prevalent than discrimination based on sexual orientation, nationality/ethnicity, physical disability, and religious beliefs. "However, despite its high prevalence, it continues to remain socially acceptable," she said.