The Only Use of

abstemious

in

In Cold Blood

He did not smoke, and of course he did not drink; indeed, he had never tasted spirits, and was inclined to avoid people who had-a circumstance that did not shrink his social circle as much as might be supposed, for the center of that circle was supplied by the members of Garden City's First Methodist Church, a congregation totaling seventeen hundred, most of whom were as abstemious as Mr. Clutter could desire.†
Chpt 1

Definition:

not doing too much of something such as eating or drinking