Background
The increasing problem of obesity has been observed in many lower-income countries during the last decades. China has adopted an open-market policy and experienced explosive economic growth, which has led to less food scarcity at the national level and to a remarkable transition in the structure of the diet of Chinese [
1]. The composition of the Chinese diet has been shifting towards a diet higher in fat and meat, and lower in carbohydrates and fiber [
2]. Additionally, decreased levels of physical activity and leisure are linked to increases in the prevalence of an overweight condition, obesity and diet-related non-communicable diseases [
3].
In previous reports, we examined eating habits and dietary knowledge of female students in Japan. Our results showed that irregular lifestyle was significantly related to indefinite complaint, with the majority of students having a desire to be thinner although the prevalence of students who were overweight was very low in this study sample [
4]. Universities and colleges are potentially important targets for the promotion of healthy lifestyles of the adult population. However, little is known concerning the body mass index (BMI) distribution and nutritional and health-related behavior of Chinese university students. The purpose of this study was to obtain a preliminary understanding of the relative level of BMI distribution of Chinese university students and to determine the nutritional knowledge and body-shape perceptions.
Material and Methods
This study was carried out between February 2001 and April 2002. Medical students from Beijing University (135 men and 150 women) in Northern China and Kunming Medical College in southern China (95 men and 160 women) participated in this study. A sample of 540 students aged 19 – 24 years were administered a self-reported questionnaire. The questionnaire consisted of 21 questions regarding eating, drinking and smoking habits (19 questions), with 2 questions related to dieting (trying to lose weight). Self-reported height and weight were used to calculate BMI (kg/m
2). The questionnaire was designed by the authors and based on a national dietary survey held by the Health and Labor Ministry of Japan. Some of the authors also traveled to China to investigate the dietary life of Chinese to facilitate questionnaire design. The questionnaire was first written in Japanese and then translated to Chinese utilizing fluent bilingual linguistic services. The translated Chinese version was back-translated to insure the original meaning was not lost. Informed consent was obtained from all participants of this study according to the Declaration of Helsinki. The statistical software package SPSS 10.0 was used for the analysis of data [
5]. In this study, parametric variables were analyzed using the Student's
t-test. Chi-square analyses were conducted for non-parametric variables. All analyses were two-tailed, and a 'p' value less than 0.05 was considered statistically significant.
Discussion
This study aimed to determine the health, nutritional knowledge and dietary behavior of university students in China. As a result, we recorded the distribution of BMI among Chinese students and found a low prevalence of obesity, a finding that is consistent with a study of Japanese female students (BMI≥25 overweight was 5.8%, BMI>30 of obesity was 0%) [
4]. In the United States, 35% of the college students are reported to be overweight or obese (BMI≥25) [
7]. According to the WHO definition of obesity, BMI>30 is the cut-off point [
6]. The definition is based on research of Caucasian populations. Asian populations are reported to have a higher body fat (%) at a lower BMI compared to Caucasians [
8]. The WHO expert consultation reported that BMI in Asian populations is related to disease at a lower level [
9]. In order to compare obesity prevalence between ethnic groups, BMI cut-off points for Asians need to be considered by well constructed and standardized body composition studies. It is notable that in China, the prevalence of overweight individuals increased from 1991 to 1997, with the increasing rate changing from 6.4 to 7.7 [
10]. The proportion of energy derived from the fat of both vegetable and animal sources increased each year. A recent study revealed that energy derived from dietary fat accounted for more than 30% of the total energy [
11]. Changes in dietary composition, which correspond to socioeconomic growth, may accelerate the prevalence of obesity in China.
The results of our study show that the majority of students regularly eat three times per day, and almost 80% of students eat vegetables and fruit twice per day. These eating habits ought to be encouraged. The traditional Chinese diet contains plenty of vegetables and is rice-based. The present study reported a high proportion of Chinese students eat breakfast daily. In contrast, a dietary survey of young Japanese subjects revealed a low rate of individuals engaged in regular eating patterns [
12]. The skipping of breakfast has been associated with lower nutritional status and the risk of cardiovascular diseases [
13]. It has also been reported that less adequate breakfast habits may contribute to the appearance and further development of obesity [
14]. Therefore the importance of regular eating patterns cannot be overemphasized in nutritional education.
Our results showed that body figure perception was significantly different between female and male students. A number of researchers have investigated the relationship of body image and gender role. Women tend to desire a thinner figure, express more anxiety about becoming fat, and are more likely to diet than men [
15,
16]. In contrast, men have reported a desire for a heavier physique and muscularity [
17]. In recent years, eating disorders have been increasing dramatically among young women. The results of our study did not confirm this suggestion to the level of statistical significance; however, it is worth pointing out that 65.0% of female students with BMI<20, which is under to normal weight range, indicated a desire to be thin. Dissatisfaction with body figure and eating disorders are closely related [
18‐
20]. Being young, female, and dieting are identified risk factors that have been reliably linked to the development of eating disorders [
21]. It was speculated that some of the students who were preoccupied with a thin body may develop eating disturbances. Thus, the promotion of healthy weight management practices should be considered when developing health education programs.
Conclusions
In conclusion, our findings reveal that the majority of students were classified into the normal BMI group, with the prevalence of BMI >30 obesity being very low in this study sample. Young female students had a greater desire to be thinner than male students. Habits involving regular eating patterns and vegetable intake were found and represent practices that ought to be encouraged. The meal and snack patterns in Chinese students were very similar to the traditional eating pattern model, although diets are changing rapidly in China and other low-income countries. The university and college arenas represent the final opportunity for nutritional education of a large number of students from the educator's perspective. Our findings suggest the need for strategies designed to improve competence in the area of nutrition, especially with respect to information relating to sources of nutrition and healthy weight management. Furthermore, public demand for health and nutritional information should be taken into consideration when implementing strategies aimed at improving the nutritional well-being of individuals.
Acknowledgements
The authors express their appreciation for the invaluable partnership and support of Dr. Wang of Beijing University, Dr Zhao of Kunming Medical College and all the study participants of both institutes. We also thank Dr. Shigeki Minakami for valuable comments on the manuscript.
Authors' contributions
R.S carried out questionnaire design, manuscript drafting and total coordination of the study. K.T has been involved in drafting and revision of the article. R.A contributed to the data entry and its analysis. L.CJ contributed to the questionnaire design, data collection and language translations. N.S contributed to final approval of the manuscript.