The present study aimed to determine whether decreased masticatory performance and tongue-lip motor function are associated with an increased incidence of adverse health events in patients with metabolic disease. One thousand patients with metabolic diseases including diabetes, dyslipidemia, hypertension, and hyperuricemia were recruited. Masticatory performance was assessed using a gummy jelly test, wherein glucose elution from chewed gummy jelly was measured. The tongue-lip motor function was measured using repeatedly pronounced syllables per second. Their association with the incidence of adverse health events (a composite of all-cause death, cardiovascular disease, bone fracture, malignant neoplasm, pneumonia, and dementia) was investigated using the generalized propensity score (GPS) method. During a median follow-up period of 36.6 (interquartile range, 35.0-37.7) months, adverse health events were observed in 191 patients. The GPS adjusted dose-response function demonstrated that masticatory performance was inversely associated with the incidence of adverse health events. The 3-year incidence rate was 22.8% (95% confidence interval, 19.0-26.4%) for the lower quartile versus 13.6% (10.5-16.7%) for the upper quartile (P<0.001). Similarly, the tongue-lip motor function was inversely associated with the incidence of adverse health events, with a 3-year incidence rate of 23.6% (20.0-27.0%) for the lower quartile versus 13.2% (10.4-15.9%) for the upper quartile (P<0.001). Decreased masticatory performance and tongue-lip motor function were associated with an increased incidence of adverse health events in patients with metabolic disease.