abstainer       
noun [ C ] uk/æbˈsteɪ.nər/ us/æbˈsteɪ.nɚ/
 禁欲者
someone who does not do something, especially something they would like to do
  His grandfather was a lifelong abstainer who never touched a drop of alcohol. 他祖父一生都是一个滴酒不沾的禁欲者。 
 Animal rights should extend to geese, say French foie gras abstainers. 动物权益(保护)应该扩展到鹅类,不吃法国鹅肝的人说。 
 - More examples
 - Abstainers do not necessarily enjoy better health than moderate drinkers.
 - Jimmy Carter and both Presidents George Bush were reportedly abstainers, but Bill Clinton liked cigars from time to time.
 - The government may lose the vote if there are too many abstainers.
 
See: abstain