January 2007, Vol. XXIV, No. 1
Weight gain is a major concern in patients with schizophrenia, especially in those taking atypical antipsychotics. Although the exact mechanism of weight gain associated with atypical antipsychotics is unknown, we often hear patients complain about an increase in appetite and a decrease in satiety. In fact, patients have come to our office holding a soda in one hand and a cookie in the other after finishing a fast-food meal. With an increase in total caloric intake, weight gain quickly ensues.
Management of weight gain in patients treated with atypical antipsychotics can be challenging. Strategies often focus on pharmacologic interventions or behavior modification. Although studies involving both of these approaches have demonstrated success in reversing weight gain, the ideal approach would be to provide early intervention to prevent weight gain.1-7 Several trials have attempted to minimize weight gain before the start of treatment with antipsychotics, but most of these were not randomized and controlled.8-10 Evans and colleagues10 looked at weight gain with olanzapine(Drug information on olanzapine) in a randomized controlled trial and found that individualized nutritional intervention provided by a dietitian was highly successful in reducing weight gain compared with subjects in the control group who received no nutritional intervention by a dietitian (2.0 kg vs 9.9 kg, P < .013) after 6 months of treatment. A study by Aquila and Emanuel,11 conducted in a residential care center, found that patients treated primarily with olanzapine were able to maintain a stable weight over 2 years by consuming a 2000-calorie diet with restrictions on soda, juice, and second portions.
Based on the success of other programs, Nguyen and colleagues implemented a diet modification program, dubbed the WIN Nguyen diet, designed to minimize atypical antipsychotic induced weight gain at the acute psychiatric ward at the University of California, Irvine (UCI) (Table). The WIN Nguyen diet includes 4 simple nutritional changes: (1) the elimination of second servings, (2) the replacement of high-calorie snacks with fruits and vegetables, (3) the elimination of desserts, and (4) the substitution of water for sodas and juices. This diet was enforced for all hospitalized patients in the psychiatric unit.
The WIN Nguyen diet is designed to reduce hunger and enhance satiety, which addresses 2 of the main side effects noted by patients taking atypical antipsychotics.12-15 Restricting meals to single portions ensures that patients have adequate time to appreciate feelings of satiety. This teaches patients that additional meals are not necessary to satisfy initial feelings of hunger. Eliminating desserts and sodas reduces the ingestion of high-calorie foods that only satisfy a patient's appetite temporarily and often cause cravings for additional high-calorie foods.16 Replacing high-carbohydrate, high-calorie snacks with fruits and vegetables allows patients to satisfy their hunger with low-calorie foods that contain large amounts of fiber, thereby slowing absorption time and increasing the duration of satiety.17 These diet changes can help reduce a patient's appetite and increase the duration of satiety.
Implementation of the WIN Nguyen diet at UCI resulted in improved weight and body mass index (BMI) profiles in 143 patients who had schizophrenia or schizoaffective disorder treated with olanzapine. A 6-year retrospective review showed that patients hospitalized prior to diet changes experienced a weight gain of 9.4 lb over 22.7 days.18 In comparison, patients hospitalized after diet modification gained a significantly lower 3.7 lb over 20.2 days (P < .0001). BMI changes had a similar pattern and increased by a significantly larger amount in patients who received a standard diet (1.5) than in patients with diet modifications (0.61) (P = .003).
Unlike the Atkins diet or South Beach diet, the WIN Nguyen diet is not a weight-loss program. It is a diet that addresses cravings and increases in appetite by instituting healthier nutrition practices. Many patients who successfully implement the WIN Nguyen diet notice a significant decrease in cravings for sugar and carbohydrates after several weeks.
Challenges in implementing a diet program
There were many challenges encountered in implementing the WIN Nguyen diet at the acute psychiatric ward at UCI. Before the diet changes, it was extremely common for patients to consume double portions at most meals. Snacks would include ice cream, cookies, cake, or potato chips. Fruits and vegetables were rarely available, and soda was readily consumed.
In addition, family members would often bring in additional food and patients were allowed to order take-out food from restaurants. Given the combination of increased appetite and nearly unlimited food, it was no surprise that many of our patients gained a significant amount of weight during their inpatient hospital stays. It required time and patience to change a routine that had been practiced for many years.
The following case vignette illustrates some of the challenges faced during the implementation of the WIN Nguyen diet.