nonindulgent
/ˌnɑnɪnˈdʌldʒənt/
adjective
- Not allowing oneself or others to have or do things that are enjoyable but not necessary; strict or restrained.
- Her nonindulgent parents set strict rules about screen time.
- The teacher was nonindulgent, expecting students to complete all assignments on time.
- He followed a nonindulgent diet, avoiding sweets and snacks.