Patients with schizophrenia can experience varying degrees of weight gain during medication treatment, which has become one of the important adverse effects of antipsychotic drugs. Weight gain is not only detrimental to patients’ physical health, but also has a great impact on their psychological health and is one of the important factors affecting treatment adherence. Therefore, weight gain has attracted increasing attention and focus. It has been reported in the literature that about 50% of patients experience significant weight gain after long-term use of typical and/or atypical antipsychotics. Common medications that tend to cause weight gain: clozapine, olanzapine, thioridazine, chlorpromazine, risperidone, haloperidol, and fluphenazine. Weight gain is associated with the strong 5-HT2., Hi and M3 receptor affinity of the drug. Concomitant impaired glucolipid metabolism and triggering of type 2 diabetes with clozapine have been reported in several publications. When selecting a therapeutic agent, patients with weight problems or a family history of diabetes should choose a drug that has as little effect on body weight as possible.