expression
eating moderately keeps the doctor away
Proverb advising that stopping at 80% fullness promotes health and reduces the need for medical care.
腹八分目に医者いらずと言うから、食べ過ぎないようにしている。
They say eating moderately keeps the doctor away, so I try not to overeat.
A traditional Japanese proverb. The exact origin is uncertain, but it reflects the cultural value of moderation in eating for health.