Translation guide
Describes a state of poor physical or mental health, or something that causes it. Japanese uses different words depending on whether you're talking about a person's condition, a habit, food, or an environment.
Describing someone who is not well, often chronically or in a weakened state.
General term for being unhealthy, often used for lifestyle-related poor health. Can describe a person or a habit.
He leads an unhealthy lifestyle.
You look unhealthy.
Literally 'physical condition is bad'. Used when someone feels unwell, often temporarily.
I'm feeling unwell today.
Constitutionally weak or sickly; implies a long-term delicate health condition.
She was a sickly child.
Describing food, eating habits, or diet that negatively affect health.
Common phrase meaning 'bad for the body'. Used for food, habits, etc.
Fast food is unhealthy.
Staying up late is unhealthy.
Literally 'not good for health'. Slightly more formal than 体に悪い.
That diet is unhealthy.
Direct translation 'unhealthy food'. Understandable but less natural than 体に悪い.
May sound slightly stiff or translated. Prefer 体に悪い in conversation.
Describing an unhealthy mind, obsession, or emotional condition.
Describing a workplace, relationship, or situation that is harmful to well-being.
Describing a pale, thin, or sickly look.
Saying 不健康な食べ物 is grammatically correct but sounds like a textbook translation. In daily conversation, 体に悪い is much more natural.
Ramen is unhealthy, but I like it.
不健康 describes a state of being unhealthy (person, lifestyle). 体に悪い describes something that causes poor health (food, habit). Use 体に悪い for external causes.
I eat nothing but unhealthy food.
Spending too much time on social media is mentally unhealthy.
You should end that unhealthy relationship.
He has an unhealthy pallor.