abstemious

restrained in eating or drinking

Roots

-ous / -ious: full of or marked by a quality
ab / abs: away, from, off, down, or apart
temetum: strong drink

Abstemious began as away from strong drink; now it means restrained with appetite or pleasure.

Her abstemious habits surprised friends who expected the celebration to be extravagant.

Ab- gives away. Temetum was strong drink. Abstemious first points to holding away from drink, then widens into restraint with food, pleasure, or indulgence.