How to say "obesity" in Japanese

• 肥満ひまんCommon
  suru verb, intransitive verb, no-adjectiveThe usual word for obesity or being overweight in general, in both everyday and medical contexts. If you need one word for 'obesity', this is the natural choice.
  運動うんどうを全然ぜんぜんしないことやら肥満ひまんやらで、彼かれは心臓しんぞう発作ほっさを起おこした。↗

  What with having no exercise and being overweight, he had a heart attack.
• 肥満症ひまんしょう
  nounObesity treated as a named medical condition or diagnosis, as by a doctor. Less common than 肥満; use it when you specifically mean the clinical disorder rather than the state of being fat.
• 脂肪過多症しぼうかたしょう
  nounA technical medical term meaning adiposis or adiposity — an excess of body fat. Rare in ordinary use; you will mostly meet it in clinical or scholarly writing rather than everyday speech.
• 肥胖ひはん
  nounA less common way to say obesity, essentially synonymous with 肥満 but rarer. It is seldom the word you want in everyday Japanese; 肥満 normally serves instead.
• 脂肪過多しぼうかた
  nounLiterally an excess of fat; glossed as obesity. A technical or descriptive term for too much fat rather than the everyday word for the condition, and uncommon outside specialist contexts.

Use 肥満 for obesity in ordinary contexts; 肥満症 for the medical condition as a diagnosis; the remaining three are rarer, chiefly clinical or technical terms for excessive fatness.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 肥満ひまんcorpulence
• 肥満症ひまんしょうobesity
• 脂肪過多症しぼうかたしょうobesity
• 肥胖ひはんobesity
• 脂肪過多しぼうかたobesity
• 貫禄かんろくcorpulence