US Adult Obesity Rate Was 41.9% in 2017 to March 2020
Medically reviewed by Medical Advisory Board Last reviewed 2026-05-13
The cited estimate covers adults aged 20 and older during 2017 to March 2020
The US adult obesity rate was 41.9% among adults aged 20 and older during 2017 to March 2020. The Centers for Disease Control and Prevention (CDC) reports that 9.2% of adults had severe obesity during the same period.
Those percentages describe the stated survey period. They do not establish a rate for a later period. CDC also reports earlier prevalence figures, differences among population groups, and medical costs for adults with obesity. Each figure answers a different question, so its population and time period matter.
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Obesity affected 41.9% of US adults aged 20 and older during 2017 to March 2020, according to CDC. Severe obesity affected 9.2% of adults in that period. Both percentages describe prevalence: the share of adults in a specified population who met the relevant body mass index threshold.
The severe obesity figure is part of the obesity figure. An adult who meets the severe obesity threshold also meets the obesity threshold, so adding 9.2% to 41.9% would count those adults twice. The figures also have a defined age range. They should not be described as rates for children or for every person living in the United States.
CDC reports the estimate for a period ending in March 2020. The cited figures alone cannot answer what share of adults had obesity after that period.
CDC Definitions of Obesity and Severe Obesity
CDC defines obesity as a body mass index (BMI) of 30.0 or higher and severe obesity as a BMI of 40.0 or higher. The severe obesity threshold falls within the broader obesity category. These definitions explain why the reported severe obesity prevalence is a subset of overall obesity prevalence.
| Category | CDC body mass index threshold | Reported adult prevalence, 2017 to March 2020 |
|---|---|---|
| Obesity | 30.0 or higher | 41.9% |
| Severe obesity | 40.0 or higher | 9.2% |
The thresholds define the categories used in these population statistics. A prevalence figure counts people who meet a category threshold; it does not describe an individual adult's blood pressure, diabetes status, or medical costs. Questions about an individual's health belong in a clinical assessment.
Change in Obesity Prevalence Across Survey Periods
CDC reports that adult obesity prevalence rose from 30.5% in 1999 to 2000 to 41.9% in 2017 to March 2020. Severe obesity prevalence rose from 4.7% to 9.2% across those same periods. The comparison describes the difference between the earlier and later figures; it does not explain why the figures changed.
| Measure | 1999 to 2000 | 2017 to March 2020 |
|---|---|---|
| Obesity prevalence | 30.5% | 41.9% |
| Severe obesity prevalence | 4.7% | 9.2% |
Both obesity measures were higher in the later period. The table keeps severe obesity separate from overall obesity so that the two trends can be read without treating them as separate populations. It also stops at March 2020. No figure in this comparison shows whether either rate changed afterward.
Obesity Prevalence by Group
CDC reports different obesity prevalence figures among the population groups listed for 2017 to March 2020. The figures are 49.9% for non-Hispanic Black adults, 45.6% for Hispanic adults, 41.4% for non-Hispanic White adults, and 16.1% for non-Hispanic Asian adults.
| Adult population group | Obesity prevalence |
|---|---|
| Non-Hispanic Black adults | 49.9% |
| Hispanic adults | 45.6% |
| Non-Hispanic White adults | 41.4% |
| Non-Hispanic Asian adults | 16.1% |
Each percentage refers to adults within the named group, rather than to that group's share of all adults with obesity. The percentages therefore cannot be added to produce a national rate. They also do not explain the differences between groups. The 41.9% overall figure and the group figures describe different denominators, even though they come from the same reported period.
A group prevalence figure cannot determine whether a particular adult meets the BMI threshold. The distinction matters when a population statistic is read alongside a person's own measurements or medical history.
Conditions and Medical Costs Associated with Obesity
Among adults with obesity, 58% have high blood pressure and approximately 23% have diabetes, according to CDC. The denominator for both condition figures is adults with obesity. CDC does not give a corresponding rate for adults without obesity in the cited facts, so these figures alone cannot show the size of a difference between those populations.
The condition percentages also cannot be added to count adults with either condition. CDC does not state in the cited facts how many adults have both high blood pressure and diabetes. The figures describe conditions present among adults with obesity; they do not establish why an individual developed either condition.
CDC reports that annual medical costs were $1,861 higher per person for adults with obesity than for adults with healthy weight. For adults with severe obesity, the reported difference was $3,097 per person. CDC puts the total at nearly $173 billion a year in 2019 dollars.
| Cost measure | CDC figure |
|---|---|
| Higher annual medical cost per adult with obesity, compared with an adult with healthy weight | $1,861 |
| Higher annual medical cost per adult with severe obesity, compared with an adult with healthy weight | $3,097 |
| Reported annual total in 2019 dollars | Nearly $173 billion |
The per-person figures are comparisons with adults at a healthy weight. They are not an estimate of any particular adult's medical bill. The national total uses 2019 dollars, while the prevalence figures describe 2017 to March 2020. Keeping those labels attached prevents a cost figure from being mistaken for a new prevalence estimate.
Reading the Numbers for Individual Care
The US adult obesity rate describes a population, while an individual's health assessment belongs to a clinician. BMI thresholds identify the categories used in CDC's prevalence figures. The reported rates for high blood pressure and diabetes concern adults with obesity as a group and do not establish an individual's condition.
A clinician can assess an individual's measurements and health history. For further context on clinical assessment, see the obesity treatment guidelines and the discussion of metabolically healthy obesity. Questions about a personal BMI result or related health conditions can be taken to a clinician.
What to Look For in a Body-Composition Scale
A bioimpedance scale trends body fat and muscle rather than just weight — useful when the number stalls but your composition is improving. The absolute body-fat % isn't lab-accurate, so use it for TRENDS at a consistent time of day. Choose one that syncs to an app so you can watch the trend line.
Frequently Asked Questions
What percentage of US adults have obesity?
CDC reports that 41.9% of US adults aged 20 and older had obesity during 2017 to March 2020. The figure describes that period and age group. It does not establish the percentage for a later period.
What BMI counts as obesity?
A body mass index (BMI) of 30.0 or higher counts as obesity under CDC's definition. That threshold is the basis for the obesity prevalence figures cited here. A clinician can assess what an individual BMI result means alongside other health information.
What is severe obesity?
CDC defines severe obesity as a body mass index of 40.0 or higher. Severe obesity affected 9.2% of US adults aged 20 and older during 2017 to March 2020. Because the severe obesity threshold also meets the threshold for obesity, that percentage is included within the overall obesity category.
How has the US obesity rate changed since 1999?
CDC reports that adult obesity prevalence rose from 30.5% in 1999 to 2000 to 41.9% in 2017 to March 2020. Severe obesity prevalence rose from 4.7% to 9.2% across the same periods. Those figures show the change between the reported periods but do not explain its causes or establish a later rate.
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