Patients who have been prescribed gabapentin are often concerned about weight gain as a side effect. However, they should note, weight gain is a very rare side effect, observed in less than 5% of patients. In cases where weight gain does occur, it is typically a result of an increased appetite or reduced exercise caused by the drug. Some ways to avoid weight gain include eating smaller meals throughout the day, exercising when possible, and eating low-calorie snacks like fruit to help curb hunger.