Translation guide
The English word "fat" can refer to body fat, the substance in food, or the adjective describing someone or something as large. In Japanese, different words are used depending on the context, and some direct translations can be rude or unnatural.
Referring to the biological substance stored in the body.
The standard, neutral term for body fat. Used in medical, health, and everyday contexts.
運動すると脂肪が燃焼します。
Exercise burns fat.
体脂肪率を測りました。
I measured my body fat percentage.
Often used for excess or unwanted body fat, like flab. Slightly colloquial.
Referring to the fatty part of meat, or oil/grease used in cooking.
General term for fat or oil, including animal fat and cooking oil. Can refer to the fatty part of meat or grease.
Saying someone is fat, either descriptively or pejoratively.
He is fat. · She's gotten fat.
The most common and relatively neutral way to say someone is fat. It's a verb phrase meaning 'to be fat'. Still, it can be direct, so use with care.
While neutral, directly calling someone 太っている can be rude. Often softened with ちょっと or ぽっちゃり.
彼は少し太っている。
He is a little fat.
Saying an animal is fat, often for livestock or pets.
Same as for people, but less socially sensitive for animals.
太った猫が道を歩いている。
A fat cat is walking down the street.
Saying something like a book, wallet, or envelope is fat (thick).
Expressing that something is very unlikely.
Literal translation: 'the possibility is low'. Natural way to express slim chance.
彼が来る可能性は低い。
Fat chance he'll come.
Calling someone 太っている (fat) directly can be very rude in Japanese, even if it's a factual description. It's often better to use softer expressions like ぽっちゃり or to avoid commenting on weight altogether. In formal or polite situations, use 太った方 (ふとったかた) or simply describe the person without mentioning weight.
あの方は少し太っていらっしゃいます。
That person is a little overweight. (polite)
脂 (あぶら) is a broader term that includes animal fat, grease, and cooking oil. 脂肪 (しぼう) specifically refers to body fat or the chemical substance fat. In food contexts, 脂身 (あぶらみ) is the visible fat on meat, while 脂肪分 (しぼうぶん) is the fat content in nutritional information.
お腹のぜい肉が気になる。
I'm concerned about my belly fat.
この肉は脂が多い。
This meat has a lot of fat.
フライパンに脂をひいてください。
Please grease the frying pan.
Specifically the fatty part of meat, like the white streaks in beef or pork.
脂身を取り除いてください。
Please trim off the fat.
Fat content, used in nutritional contexts.
この牛乳は脂肪分が少ない。
This milk is low in fat.
A softer, somewhat affectionate term for chubby or plump. Often used for babies, or to describe oneself in a self-deprecating but cute way.
ぽっちゃりした猫が好きです。
I like chubby cats.
A blunt, often derogatory term for a fat person. Can be used jokingly among close friends but is generally insulting.
Avoid using this unless you are very close to the person and it's clearly a joke.
デブって言わないで！
Don't call me fat!
Medical/formal term for obesity. Used in health contexts.
肥満は健康に悪い。
Obesity is bad for your health.
Plump, nicely fat, often with a positive connotation for animals.
丸々と太った犬が寝ている。
A plump dog is sleeping.
Used for flat objects like books, slices of meat, etc. Means thick.
分厚い財布を持っている。
He has a fat wallet.
General word for thick. Can be used for books, walls, etc.
この本はとても厚い。
This book is very fat.
Means 'impossible' or 'no way'. Stronger than 'fat chance'.
彼が謝るなんてありえない。
Fat chance he'll apologize.