Hypermetabolic conditions with nutrition deficiencies are common in patients with extensive burns. Balanced nutrition status is required to achieve adequate wound healing. Mental disorder, which tended to make a patient uncooperative, complicates the management. We report the case of a 35-year-old man with schizophrenia who suffered full- and partial-thickness burns in approximately 38% of total body surface area due to attempted suicide. The patient was hospitalized for 66 days and underwent multiple surgeries. His body mass index (BMI) was continuously low. Tissue injuries provoked inflammatory responses that contributed to metabolic disarrangement, meanwhile the presence of psychiatric disorder complicated the means of nutrition assessment and therapy needed to compensate for the high nutrition demand during the treatment period. Nutrition support should be assessed and adjusted continuously.