obesity

American  

[oh-bee-si-tee] / oʊˈbi sɪ ti /

Sometimes obeseness

noun

1. the condition of being very fat or overweight; corpulence.

   His obesity puts him at risk for major health problems.

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obesity Scientific  

/ ō-bē′sĭ-tē /

1. The condition of being obese; increased body weight caused by excessive accumulation of fat.

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Other Word Forms

• antiobesity
  adjective
• overobesity
  noun

Etymology

Origin of obesity

First recorded in 1605–15; from Middle French obésité, from Latin obēsitāt-, stem of obēsitās, equivalent to obēs(us) obese ( def. ) + -i- ( def. ) + -tās -ty ² ( def. )

Compare meaning

How does obesity compare to similar and commonly confused words? Explore the most common comparisons:

• anorexia vs. obesity

Explanation

Obesity is the condition of being more overweight than is considered average or healthy. The noun obesity was first used around 1610 and has origins in the Latin word obesitas, meaning "fatness" or "corpulence." During the Middle Ages, obesity was a sign of wealth and prosperity indicating that you had enough money to buy and eat all the food you wanted while others starved. Nowadays, research has shown that having too much fat can cause a number of related health problems. A healthy diet and fitness regime is a great way for someone to shed excess pounds and avoid obesity.

Example Sentences

Obesity has long been known to increase the risk of many diseases.

From Science Daily • Apr. 11, 2026

Obesity pills are the newest frontier for weight-loss drugs.

From The Wall Street Journal • Apr. 1, 2026

"But medication alone will not reverse the global rise in obesity. Obesity is a complex, chronic disease," he said, noting the importance of prevention efforts and healthier environments.

From Barron's • Mar. 20, 2026

Obesity rates steadily increased until 2023, when they dropped for the first time since 2011.

From MarketWatch • Mar. 18, 2026

Rather, it’s the advertisements for junk food, notes the Harvard School of Public Health in a health advisory titled “The Small Screen Looms Large in the Obesity Epidemic.”

From "A Deadly Wandering: A Mystery, a Landmark Investigation, and the Astonishing Science of Attention in the Digital Age" by Matt Richtel