abstemious
Abstemious (adj) means eating and drinking only small amounts, especially of alcohol, in a careful, controlled way.
Etymology
Abstemious comes from Latin abstēmius (“abstaining from wine”), formed from ab, abs (“from”) and tēmus, a root of tēmētum (“intoxicating drink, especially strong mead or wine”) — possibly from Proto-Indo-European *temH- (“dark (referring to the colour of wine)”) — plus -ous.