The Affordable Care Act forbids health insurers to deny coverage or impose higher premiums on people with pre-existing medical conditions. Yet one sort of pre-existing condition seems to have escaped the ban: your weight.    

Insurance companies are allowed to charge higher health insurance rates to people whose body mass index (BMI) – a common measure of obesity – is too high. On the BMI scale, a person with a score above 25 is considered overweight; above 30, obese, above 40, morbidly obese. People with BMIs above 30 or 31 can see an increase in their insurance premiums of as much as 25%; if their BMI is more than 39, they can be charged 50% more than someone with a BMI of 25. (See How does being overweight affect my healthcare costs?)

Why the higher rates? The rationale is that those with weight problems tend to have more medical problems, which lead in turn to higher medical bills. According to a 2012 Journal of Health Economics study, obese men had an additional $1,152 annually in health expenses, like prescriptions and hospital visits, and obese women cost an additional $3,613.  A 2019 report from the Organization for Economic Cooperation and Development (OECD) showed that obese people require 2.4 times more prescriptions that people who are at a healthy weight, are hospitalized longer, and often need treatments that are both costlier and longer.

Key Takeaways

  • Health insurance companies are legally allowed to set premiums for overweight and obese Americans that are higher than those of their healthy-weight counterparts.
  • This reflects statistics that show overweight and obese Americans generally have higher prescription costs, longer hospital stays and more extensive medical treatment needs.
  • When setting premiums, body mass index (BMI) is generally used as a determinant of health and obesity, but recent research shows that BMI is a flawed and sometimes inaccurate metric.
  • A person can have a BMI that would classify them as overweight, but still be otherwise healthy; similarly, a person can have a BMI that is classified as healthy but still have other medical issues that leave them unhealthy.

Is BMI the Best Test?

What other data show, though, is that having a high BMI does not necessarily determine that one is unhealthy. In a new study, published in the International Journal of Obesity, a team of UCLA psychologists found that the “data show there are tens of millions of people who are overweight and obese and are perfectly healthy," according to lead author A. Janet Tomiyama.    

More specifically, the study found “close to half of Americans who are considered ‘overweight’ by virtue of their BMIs (47.4 percent, or 34.4 million people) are healthy, as are 19.8 million who are considered ‘obese.’” And “30 percent of those with BMIs in the ‘normal’ range – about 20.7 million people – are actually unhealthy based on their other health data.”     

These findings are similar to another study published in the European Heart Journal. U.S. and European researchers who looked at data from 43,265 enrollees in a 1979-2003 Aerobics Center Longitudinal Study found that many obese participants were “metabolically healthy,” provided they also didn’t have other poor-health markers such as high blood pressure, diabetes, high triglycerides or low levels of good cholesterol. Nearly 50% of the obese participants qualified as metabolically fit. And these "fat but fit" individuals posed no risk of dying earlier than normal-weight participants. 

A recent study from the OECD shows that the United States healthcare system bears the biggest financial burden when it comes to battling obesity. Obesity is forecast to cost the U.S. health system $644 per person on average annually between 2020 and 2050, or 14% of total U.S. healthcare spending.

Ethical Questions

Whether or not BMI should be "a proxy for whether a person is considered healthy," to quote UCLA's Tomiyama, a more fundamental question exists: Is it fair to for insurers to penalize the overweight with higher rates because they cost the companies more? Doing so could start us down a slippery slope, warns Mikael Dubois of Stockholm's Royal Institute of Technology Division of Philosophy, in a Journal of Primary Prevention paper. Such a practice, “if applied consistently, would raise thorny issues about similar issues, like genetic disorders, which most people would find ethically unacceptable (e.g., should a family with a child born with cerebral palsy be charged more, following the same logic of actuarial fairness?).” 

Dubois even questions if the higher-costs argument is accurate. If one studies annual medical expenses for unhealthy versus healthy people, one might find the unhealthy rack up higher costs, true. But unhealthy people tend to die earlier in life, so the total costs over a lifespan may be equal to that of a healthy person's, or even lower (since healthier people live longer and are bound to encounter increasing problems as they age).


The percentage of Americans classified as obese, according to the most recent statistics from the National Center for Health.

Voices for Change

Higher premiums for people with unhealthy habits is not new: It's currently common (and much less controversial) for smokers to pay steeper rates than non-smokers, for example. But the situations aren't parallel, says Michael Wood, president of a health consulting firm in Edmonds, Wash. Smoking, he argues, seems more like a choice than gaining weight: “You don’t have to smoke to live; you have to eat to live.”

It can also be much harder to improve one's condition. Often companies waive the higher rates if the affected individual participates in a program to change unhealthy behaviors (and shows results, eventually). But while there are successful programs to quit smoking, weight-loss programs seem much less effective.

“For years, the country’s ‘wellness’ industry has offered health-enhancement and obesity-reduction programs to corporations, from gym memberships to dietary counseling. For obesity, this approach has not worked. Research on these programs shows that they have not significantly reduced weight or cholesterol levels, or improved any other health outcomes,” writes Stephen Soumerai, a professor of population medicine at Harvard Medical School, in The Health Care Blog.  

The Bottom Line

Having extra pounds on your frame may translate into paying extra dollars for your health insurance premiums. Check with your company to find out if it charges people more because of their body weight or BMI, or if they're planning to. If so, find out if there is an incentive to join some type of weight-reduction or exercise program; although they don't always work, even a good-faith effort to enroll may help you avoid taking on additional financial weight.