The existence or absence of exercising habits and the physical activity status is greatly associated with obesity. Subjects who practiced exercise on a regular basis were as few as 2 in the obese group (11.1%) and 4 in the nonobese group (23.5%). Meanwhile, subjects who almost never exercised were as many as 7 in the obese group (38.9%) and 6 in the non-obese group (35.3%). Those
Table 3. Exercise, physical activity, smoking, alcohol, dietary habits and medication status.
Table 4. Nutrient intake and food intake according to food groups per day.
Table 5. Nutrient intake and food intake according to food groups per day in snacks.
were almost at the same percentages as those reported by Brown et al. in a previous study in which 36.0% of the subjects almost never exercised. Because there was no difference between the two groups in terms of exercise or physical activity, those were not considered as contributing factors to obesity.
Regarding smoking, 14 subjects in the obese group (77.8%) and 9 in the non-obese group (52.9%) were smokers. Such high smoking rates are consistent with the reports of previous studies .
As for alcohol drinking, subjects who almost never drank alcohol were as many as 12 in the obese group (66.7%), and 12 in the non-obese group (70.6%). The reasons for avoiding alcohol were either due to financial matters or for fear of negative impact of interaction with medication. The low rate of alcohol use and the reasons thereof were similar to those in the previous study conducted by Brown et al.
4.3. Antipsychotic Drugs and Body Weight Gain
The effects of therapeutic drugs have been indicated as a contributing factor to the obesity of psychiatric patients [7,11]. Currently, atypical antipsychotic medications are frequently being used more and more in their pharmacological treatment, and consequently, side effects such as weight gain and abnormal glucose tolerance has become a controversial issue. Although more than a single mechanism is involved in the weight gain induced by antipsychotic drugs, clonzapine and olanzapine are said to be the atypical antipsychotic medications which cause weight gain most easily [12-14]. In this study, we examined whether the patients’ antipsychotic medications were typical or atypical, and we examined their association with obesity. As a result, 14 subjects (77.8%) in the obese group took atypical antipsychotic medications, but so did as many as 10 subjects (55.8%) in the non-obese group. And no significant difference was found between the two groups. Thus, atypical antipsychotic medications could not be considered as the contributing factors to the obesity of the subjects in this study.
The dietary survey was performed on the basis of food records while using photographs as references for the conversion of the food quantity into weight in order to calculate the nutrient intake and the food intake according to food groups. We examined the existence or absence of differences between the two groups on the basis of 5 patterns: breakfast, lunch, dinner, snack, and oneday meal.
First, the nutrient intake from snacks in the obese group was significantly higher than that of in the nonobese group, in terms of energy and ten other nutrients. In addition, in food groups, the intake of favorite foods in the obese group was significantly higher than that of in the non-obese group. In other words, it was revealed that the snacks were one of the main contributing factors to the obesity of the study subjects.
However, regardless of the fact that the energy from snacks in the obese group was significantly higher (P = 0.002) than that of in the non-obese group, no significant difference was found between the two groups in terms of energy in one-day meals including snacks. And yet, the average amount of energy (standard deviation) in a oneday meal was 2267 (SD517) kcal in the obese group and 2000 (SD320) kcal in the non-obese group. The values in the obese group were 267 kcal higher. In addition, the average amount of energy in snacks was 308 (SD308) kcal in the obese group and 77 (SD107) kcal in the nonobese group. The values in the obese group were 231 kcal higher. The differences between the two groups in terms of amount of energy in one-day meals and in snacks were almost identical. These facts suggest that the obese group consume about 250 kcal more per day than the non-obese group, and that this would be due to snacks. The absence of significant difference is thought to be due to the small number of study subjects. In addition, according to previous studies, obese individuals tend to underreport their consumption when filling out the food record [15-18]. If similar tendencies were also observed in this study, it is possible to conclude that there could have actually been significant differences in energy between the obese group and the non-obese group.
On the other hand, as a result of a four-day dietary survey using the food record method, Henderson et al. reported that patients with schizophrenia had a significantly higher BMI but their energy intake was significantly lower than those of ordinary people. That is similar to the results of this study. As for the reason why they become obese despite the fact that their energy intake is almost the same or less than that of ordinary people, the findings of this study showed that snacks are one of the main contributing factors to the obesity of the subjects, and, in that consideration, the problem is primarily the timing of the snacks. When a person eats supper later than at 10:00 pm, sleeps immediately, and eats again in the middle of the night when he/she feels hungry, this facilitates energy intake and its conversion into fat, and results in an increase in adipose tissue mass . Next is the problem of the quality of the snacks. The results of this study showed that the obese group had a significantly higher carbohydrate intake than the non-obese group in terms of one-day meals including snacks. If the ratio of the amount of simple sugars in those carbohydrates is high, it could easily result in an accumulation of visceral fat. And one more issue is in the way of eating. An irregular diet including fasting, between-meal snacks and midnight snacks causes disturbance of the circadian rhythm of the metabolic system and of the endocrine system which leads to obesity.
In the future, in order to prevent obesity and lifestylerelated diseases in patients with schizophrenia, it will be essential to determine the relationship between obesity and various causes other than overeating, such as the time they eat, the type of food they eat, and how they eat.
First, there are problems with the self-administrated food record method and the 3-day period. Confirmation using photographs was performed in order to safeguard the validity of the self-administrated food records. Considering the fact that the study subjects were schizophrenic patients, jotting down records for more than 3 days proved to be difficult. Therefore, the method for conducting dietary surveys in psychiatric patients with diseases such as schizophrenia is one significant issue to be examined in the future.
Furthermore, we would like to perform highly accurate surveys closely focused on the issue of snacks revealed by this study, including the points which could not be determined this time, namely the timing of the snacks, the type of sugar they contain, and how to eat. And we hope that those will be reflected in dietary education in the future, as a preventive measure against obesity in patients with schizophrenia.
The dietary survey revealed that snacks are major contributing factors to obesity. Based on this dietary survey, it becomes necessary to focus on snacks, in addition to basic focus on balanced diet as well, to prevent further obesity in those schizophrenic patients.
We express our sincere gratitude to all the patients for their cooperation in the survey, to the physicians at Kohdo Mental Hospital, Dr. Kiyoko Tamura, Chief of the Outpatient Department, Nurse Yoshie Osaki, Nurse Maki Sato, Mr. Fumihiro Watanabe, Chief of the Division of Day Care, and to all staff members at the Department of Nutrition for their collaboration in this study.