The expression "most overindulgent" describes excessive and self-indulgent behavior. So, antonyms for this phrase might include terms like "restrained," "temperate," "moderate," "frugal," "sensible," and "temperate." These opposite terms suggest that by exhibiting restraint, individuals can maintain healthy habits and avoid the pitfalls of overindulgence. For instance, choosing to do things in moderation might result in better physical health, emotional wellness, and a more balanced lifestyle. Ultimately, striving for balance and moderation can provide individuals with a sense of self-control, helping them to make informed decisions and avoid the negative consequences of overindulgence.