The phrase "losing lunch" refers to the act of vomiting or regurgitating food. Some possible antonyms for this phrase could include words like "having a hearty meal," "feasting," "indulging," or "enjoying a delicious repast." These terms suggest the opposite of nausea, and instead convey a sense of satisfaction, pleasure, and fulfillment. Other antonyms might include words like "healthful eating," "moderation," or "balanced nutrition," which imply a state of wellness rather than discomfort. In essence, any phrase or word that suggests positive dining experiences, good health, or enjoying food without negative physical reactions could serve as an antonym for "losing lunch.