Objective: Treatment with most antipsychotics is associated with an increased risk of weight gain and metabolic disturbances. In a randomized trial, we previously demonstrated that 16 weeks of glucagon-like peptide-1 receptor agonist liraglutide treatment vs. placebo significantly reduced glucometabolic disturbances and body weight in prediabetic, overweight/obese schizophrenia-spectrum disorder patients treated with clozapine or olanzapine. The aim of this study was to investigate whether the beneficial effects of the 16-week intervention were sustained beyond the intervention period. Method: One year after completion of the intervention, we investigated changes in body weight, fasting glucose, glycated hemoglobin, C-peptide, and lipids comparing 1-year follow-up levels to end of treatment (week 16) and baseline (week 0) levels. Results: From end of treatment to the 1-year follow-up, body weight had increased in the liraglutide-treated group. However, compared to baseline levels, the placebo-subtracted body weight loss remained significantly reduced (−3.8 kg, 95% CI: −7.3 to −0.2, P = 0.04). Fasting glucose, glycated hemoglobin, C-peptide, and lipids had each returned to baseline levels 1 year after stopping liraglutide. Conclusion: The body weight reduction during 16 weeks of liraglutide treatment was partially sustained 1 year after the intervention was completed. However, the improvements in other metabolic parameters returned to baseline levels.