NEW YORK (NewsNation) — When many think of discrimination in the workplace, discrimination based on weight may not be the first thing that comes to mind. However, bias against obesity has remained steady in the office and discrimination against it is unprotected on a federal level.

A Harvard University study found that while biases on race and gender declined, biases on weight remained steady.

The wage gap between men and women is always a lightening rod topic, but now, weight can be added to that argument.

The Harvard study and several others, some with data going back nearly 20 years, reveal there is an “obesity penalty” in the workplace.

Gathering data since 2007, the Harvard study found weight bias actually increased in work environments.

Another study conducted by the Federal Reserve Bank of St. Louis estimated obese women earn between 4%-12% less than their thinner counterpoints.

The reasons behind it are a bit vague, but there’s some hypothesizing that employers may see higher body fat as a sign of poor short- and long-term health and lower productivity, according to the study.

This comes at a time when the Wall Street Journal reported some employers are cutting back on health coverage for weight-loss drugs like the popular Ozempic and Wegovy, which they estimate can cost almost $1,400 a month per employee.

But weight discrimination doesn’t just concern a paycheck, it concerns the ability to collect one at all.

Unlike race, religion and sex, weight is not a federally protected class. Michigan is the only state that has passed a law to declare weight as a category protected from discrimination, according to the Society for Human Resource Management.

In most districts, employers are free to fire someone simply because they’re overweight. But some lawmakers are trying to change that.

Back in May, New York City Mayor Eric Adams signed an ordinance under the New York City Human Rights prohibiting discrimination based on a person’s weight and height.