Characteristics of the life habits of obese students at one of Japan's National Colleges of Technology.

Aim This study clarified the characteristics of life habits of obese Japanese male students at the National Colleges of Technology, Japan. Materials and methods Healthy students aged 15-19 years answered a questionnaire containing 21 items on the following five categories of life habits: general exercise, meals, sleeping, leisure activity and illness or injury history. The subjects were divided into three groups based on the criteria of body mass index (BMI) and body fat percentage (%BF): non-obese (%BF < 20%, n = 420), overweight obese (%BF ≥ 20% and BMI ≥ 25, n = 99), and hidden obese (%BF ≥ 20% and BMI < 25, n = 60). The mean differences in waking time, bedtime and amount of time spent walking, sleeping and watching TV per day were examined using one-way analysis of variance (ANOVA) and chi-square tests for each item. Results The overweight obese and hidden obese groups engaged in less exercise time, were more likely to eat until they were full at meals and were less likely to eat between meals or late at night than the non-obese group. In addition, the non-obese group had significantly later waking times and significantly less TV-watching time than the overweight obese group. There were no significant differences with respect to leisure activity and illness or injury history among the three groups. Many students in all groups had regular waking times and were not performing any leisure activities. Conclusion The findings suggest that obese students may need further guidance to help them maintain a healthy life and appropriate weight.