• East Asian mathematical journal
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• v.34 no.3
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• pp.317-330
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• 2018

We develop a mathematical model for the obesity dynamics to investigate the long term obesity trend with the consideration of psychological and social factors due to the increasing prevalence of obesity around the world. Many mathematical models for obesity dynamics adopted the modeling idea of infectious disease and treated overweight and obese people infectious and spreading obesity to normal weight. However, this modeling idea is not proper in obesity modeling because obesity is not an infectious disease. In fact, weight gain and loss are related to social interactions among different weight groups not only in the direction from overweight/obese to normal weight but also the other way around. Thus, we consider these aspects in our model and implement personal weight gain feature, a psychological factor such as body image dissatisfaction, and social interactions such as positive support on weight loss and negative criticism on weight status from various weight groups. We show that the equilibrium point with no normal weight population will be unstable and that an equilibrium point with positive normal weight population should have all other components positive. We conduct computer simulations on Korean demography data with our model and demonstrate the long term obesity trend of Korean male as an example of the use of our model.

• Korean Journal of Community Nutrition
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• v.23 no.5
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• pp.431-443
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• 2018

Objectives: Normal weight obesity (NWO) is defined as excessive body fat in the context of a normal body mass index (BMI). This condition carries a greater risk of developing noncommunicable chronic disease and has been associated with early inflammation. This study was conducted to compare the anthropometric measurements, eating behaviors, and blood clinical indices among four groups: underweight, normal, normal weight obesity and obesity. Methods: The subjects included 215 female college students. A questionnaire was administered regarding general characteristics, dietary behaviors, food consumption frequency. Anthropometric measurements and blood clinical indices were also investigated. Results: The average BMI, body fat percentage, waist circumference, fat-free mass, and muscle mass were highest in the obesity group (p<0.05). Most subjects had tried to lose weight and perceived that their health was worse than before they became college students. The ratio of students in the NWO group who thought their health was very poor was significantly higher than in the other three groups (p<0.05). The obesity and NWO groups seemed to eat more and their eating speed was significantly faster than the other groups (p<0.001). The consumption frequency of caffeinated beverages was significantly higher in the NWO group than in the other three groups (p<0.01). WBC was significantly higher in the obesity group (p<0.05). Serum levels of TG and total cholesterol were also significantly higher in the obesity group (p<0.05). Serum GPT was significantly higher in the obesity group (p<0.05) while BUN level was highest in the NWO group (p<0.05). Conclusions: The obesity group showed the most health problems while the NWO group seemed relatively healthy. However, NWO can lead to problems such as metabolic syndrome and cardiovascular disease in later life if poor dietary habits are maintained. Therefore, education in appropriate eating habits is needed for these subjects.

• Journal of Oriental Neuropsychiatry
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• v.14 no.1
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• pp.183-192
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• 2003

Objective : Obesity is related to psychological problems as well as physical problems. This study was designed to investigate the depression of over weight and normal group who visited to obesity clinic for diet therapy. Methods : 67 patients were selected(obesity group 42, normal group 25), they were treated medically in obesity clinic of Dong-Seo Oriental Hospital. We checked age, sex, education level, relative weight, BMI and Beck Depression Inventory(BDI) in two group. Results : The results were summarized as followed. 1. The ratio of Relative Weights are $137.45{\pm}12.77$ in over weight group, $108.48{\pm}9.11$ in normal group. 2. The ratio of BMI are $28.61{\pm}2.94$ in over weight group, $23.04{\pm}1.83$ in normal group. 3. The results of BDI score are $10.60{\pm}7.15$ in over weight group, $12.56{\pm}8.33$ in normal group. Conclusions : These results suggested that the patients who participated in diet therapy had mild depression and we should pay attention to psycological problem as well as the physical problem when we treat obesity.

• Preventive Nutrition and Food Science
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• v.14 no.2
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• pp.116-122
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• 2009

The principal objective of this study was to assess the weight control behavior, body shape satisfaction, and obesity stress depending on the degree of obesity in college students who applied for a weight control program. The average BMI of the participants was $21.4\;kg/m^2$ which was in the normal range, and 76.3% of the participants were of normal body weight. Ideal BMI in this participant was $18.1\;kg/m^2$, which is in the underweight range. In terms of body perception, participants generally overestimated their body weight. The overweight and normal weight groups were less satisfied with their body shape than was the underweight group. The overweight group also expressed fears of showing their bodies to others. Additionally, the overweight and normal groups exhibited higher obesity stress than the underweight group. 97.0% of participants were interested in weight control as a way to improve their appearance. They usually obtained their weight control information from the internet and mass media. More than 80% of participants had weight control experience, having undergone weight control attempts for duration of less than a month. However, after the discontinuation of weight control efforts, these participants regained the weight. As a consequence, they were generally unsatisfied with the outcomes of weight control programs. This study demonstrated that the college women who had applied for the weight control program were unsatisfied with their body shape owing to distorted notions of the ideal body shape, and these women had generally undertaken frequent efforts to control their body weights. These results underline the importance of educating college-aged women on proper body perception and the maintenance of healthy body weight and shape.

• Journal of Nutrition and Health
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• v.31 no.7
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• pp.1158-1164
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• 1998

This study was carried out to provide information on the related factors for child obesity through investigation of children aged 6-12. Data was obtained on family history, dietary habits and physical examinations. Children were classified into normal(98 persons) and obese (108 persons) groups using combinations of the height f3r age, weight fir age, and weight fir height standards used by the World Health Organization. Children's height, weight and BMI showed significant differences between groups except children aged 8 for height. Birth weight, breast feeding and unbalanced diet were not associated with obesity. Overeating was a risk factor in the obese group(Odd ratio : 3.417, 95% CI 1.879-6.212). Taking nutrition pills was correlated to obesity. Odd ratio for taking nutrition pills was 0.109(95% CI : 0.024-0.492) between normal and obese group. Number of brothers didn't have any correlation to obesity. Obesity was not correlated to mother's education level or employmental status. As the result of this study, children's obesity was related to overeating and taking nutrition pills. Therefore, these results suggest that systematic dietary education and continuous parental supervision are necessary to avoid child obesity. (Korean J Nutrition 31(7) : 1158-1164, 1998)

• Korean Journal of Health Education and Promotion
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• v.9 no.1
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• pp.88-102
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• 1992

The exact estimation of physical growth by Obesity level has important meaning to the health care and evaluation on adolescent girls. So this study tried to clear the relationship between weight and body fat by using data for the height, weight of 124 elementary school children and high school student in Seoul. Then this study tried to show the physical growth pattern and various characteristics by Obesity level by using longitudinal for the height, weight of 1113 high school students in Seoul, and it also tried to show what influencing factors on the physical growth of this aged population. The result could be summarized as follows. 1. The relationship between weight and body fat(%) has 0.81475(r) at age 9 and 0.69361(r) at age 18. Also the relationship between weight and lean body muscle(LBM %) has -0.81470(r) at age 9 and -0.64729(r) at age 18. 2. The weakness, normal and obesity groups were classified by Obesity level. In case of weakness group showed the very low Obesity level at age 8 to 11, in case of obesity group showed the high Obesity level at age 15 to 18. Also Rohrer index was decreasing tendency up to age 12 in weakness group and increasing tendency over age 14 in obesity group. 3. When the height and weight growth pattern was compared, height growth was superior to weight growth at age 9 to 14.5 in normal group. But weight growth was inferior to height growth at age 9 to 14.5 in normal group. In obesity group, weight growth was superior to height growth at age 7 to 18. On the other hand the height growth of weakness group was superior to the normal group and the obesity group except age 11 to 12. 4. On height velocity curve by PHV age obesity group showed the most growth amount per year(9.00Cm/yr), and the next is normal group(8.77Cm/yr), weakness group(8.70Cm/yr). Then the difference between PHV age and PWV age was within 1 year in these three groups. 5. In these three groups, height velocity curve by menarcheal age showed the PHV before 2~3 years of menarcheal age. And weight velocity curve by menarcheal age showed the remarkable PWV before 1 year of menarcheal age.

• Korean Parent-Child Health Journal
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• v.14 no.1
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• pp.18-27
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• 2011

Purpose: The purpose of this study was to compare health locus of control with health-promoting behaviors according to elementary school children's degree of obesity, and to analyze correlations between two variables. Methods: Three hundreds and sixty three elementary school children were participated from three elementary schools in Seoul. Multidimensional Health Locus of Control (HLOC) scale and Health Promoting Lifestyle Profile (HPLP) were used. Results: Obese children was 16.8% of all research subjects. Internal HLOC in over weight group was higher than normal weight group (F=3.611, p=.014). Chance HLOC in under weight group was higher than other groups (F=3.553, p=.015). External HLOC in over weight and obesity group was higher than normal weight group (F=3.553, p=.015). Correlations between HLOC in internal and external and health-promoting behaviors were significant (r=.347, p<001; r=.207, p<001). Also, children who did not have siblings and have obese parents showed higher rate of obesity, and lack of sleeping time tend to be related to obesity. Conclusion: External HLOC of obesity children is higher than that of normal weight children. Meanwhile, obese children with higher internal HLOC were good at doing health-promoting behaviors. Therefore, if obese children are trained for internal health control, it can lead to their health-promoting behaviors.

• Korean Journal of Health Education and Promotion
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• v.18 no.2
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• pp.83-95
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• 2001

The purpose of this study is to describe Eating Behavior for High school boys who are obesity using three factors(dietary restraint, disinhibition, hunger). The subjects were 200 high school boys. The convenience sample is consist of 101 normal weight boys and 99 obeses weight boys. Data were collected between Mat 1 and June 20 in 2000 and analyzed using the SAS package. The results are as follows: 1. The first hypothesis was not supported that is, the normal weight boys much more doing dietary restraint than the obese boys. 2. The second hypothesis was supported that is, the obese boys more experience disinhibition than the normal weight boys. 3. The third hypothesis was supported that is, the obese boys more experience hunger than the normal weight boys. The eating behavior of obese boys is different that of normal weight boys, The obese boys more experience disinhibition and hunger than the normal weight boys, but dietary restraint was more done the normal weight boys than the obese boys.

• The Journal of Korean Society for School & Community Health Education
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• v.9 no.1
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• pp.47-61
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• 2008

Objectives: This study examined to explain the practical health behaviour and health-related quality of life, and their influencing factors in high school students. Methods: Total of 718 high school students from 1 school in Seoul were assessed with a self-administered questionnaire regarding general characteristics, health related characteristics, obesity index(Height and weight calculated by using the relative weight law: obesity group>20%, overweight group $10{\sim}20%$, normal weight group $-10{\sim}10%$, under weight group <-10%), health behaviour in school-aged children(eating, exercise and weight control) and health-related quality of life(PedsQLTM4.0 Generic Core Scale: physical health, emotional functioning, social functioning, school functioning). Results: Major results were as follows. 1. The rate of obesity by obesity index was 5.3% of high school students. Obesity incidence in adolescents was mainly associated with gender and parents whether obesity. 2. Perceived health status was lower in obese adolescents than in normal adolescents. 3. The rate of miss a breakfast was 37.9%, and obesity group than normal weight group were fruits, vegetables and milk intake at least, a lot of fastfood intake. During the past week, followed by intense physical activity, and overweight consumed a lot of time for TV and the Internet. Overall, under weight group and normal weight group belong to the students evaluated fatter than themselves. Weight control for weight loss, gain and maintain was grater in obesity group than in normal weight group. Weight loss showed highest scores in overweight group which appeared significant difference. 4. Obese adolescents compared with other groups, reported lower total QOL score and all QOL in domain, and especially social functioning showed significant differences. 5. Factors influencing the adolescents's QOL were found to be gender, perceived health status and exercise. Conclusions: High school girls were aware of their bad health status and likely to improve the QOL by practicing health behaviour. But obese adolescents were likely to degrade the quality of life by reducing the practice of health behaviors. So further school-based education about proper practical health behaviors and obesity prevention is necessary.

• Child Health Nursing Research
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• v.10 no.3
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• pp.300-310
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• 2004

Purpose: To compare normal weight children with obese children in terms of family factors, eating habits, and sociocognitive factors. Method: This study compared 217 obese children with 231 normal standard weight children of 4th-6th graders from 7 elementary schools in Kangwon province. The study also surveyed 817 their parents using questionnaires in which familial factors, eating habits, and sociocognitive factors such as dietary self-efficacy, locus of control and self-esteem were included. Result: Obese children had more obese family members, more family members with chronic metabolic disease, and lower breast-feeding rate than normal weight group. Dietary self-efficacy was positively correlated with eating habits and locus of control while no correlation was found with obesity index.. Self-esteem was negatively correlate with obesity index. Both the parents and the childrens eating habits showed significant positive correlation to the obesity index. Conclusion: These results implied familial factors, eating habits, and sociocognitive factors influenced childhood obesity. Thus, further research targeting to positive attitude toward familial dietary practices combined with significant sociocognitive factors, may lead to prevention and effective management of childhood obesity.