Effectiveness of obesity interventions among South Korean children and adolescents and importance of the type of intervention component: a meta-analysis.

BACKGROUND: Various interventions have been tested to prevent or treat childhood obesity in South Korea. However, the overall effect of those interventions is unclear, as very few reviews and meta-analyses were specific to Korean children and adolescents. PURPOSE: We aimed to examine the overall effect of obesity interventions among Korean children and adolescents, while also examining differences by sex, age group, baseline weight category, intervention duration, number of intervention components, and type of intervention components. METHODS: A meta-analysis was conducted for all intervention studies sampling Korean children and adolescents, with at least one control group and one month of follow-up, published between January 2000 and August 2020. Cohen d was calculated as an effect size for treatment effect, using the standardized difference between intervention group's body mass index (BMI) change and control group's BMI change. RESULTS: The final sample included 19 intervention studies with 2,140 Korean children (mean age, 12.2 years). Overall, interventions were strongly favored over their controls (d=1.61; 95% confidence interval [CI], 1.12-2.09). The subgroup analysis showed that interventions with at least one physical activity component (d=2.43; 95% CI, 1.63-3.24) were significantly better than those that did not include physical activity (d=0.02; 95% CI, -0.26 to 0.31). CONCLUSION: Type of intervention component appeared important, though no differential association was observed by sex, age, baseline weight category, intervention duration, and number of intervention components. Korean and non-Korean interventions may be substantively different. Additional studies are needed to understand why and how Korean interventions differ from non-Korean interventions.

Prevalence and correlates of highly caffeinated beverage consumption among Korean adolescents.

OBJECTIVE: The purposes of this study were to (1) examine the multi-year prevalence of highly caffeinated beverage (HCB) consumption, (2) identify sex differences in the prevalence, and (3) investigate relationships between HCB consumption and behavioral characteristics in a nationally representative sample of Korean adolescents. METHODS: Data from the Korea Youth Risk Behavior Web-based Survey (2014-2017) were analyzed. RESULTS: HCB consumption was higher in 2017 than 2014 (23.9% vs. 12.0%), and higher among boys than girls (17.2% vs. 13.1%). HCB drinkers were more likely to (1) be boys, (2) be overweight or obese, (3) use alcohol and tobacco, (4) consume soda at least once per week, (5) consume sweetened beverages at least once per week, (6) have seriously considered suicide during the past 12 months, and (7) have attempted suicide during the past 12 months (p<0.05 for all). CONCLUSION: Effective programs to curb HCB consumption among Korean adolescents need to be established.

Influenza Vaccination Among U.S. College or University Students: A Systematic Review.

OBJECTIVE: Influenza is one of the major causes of morbidity. This study summarized major components that influence college/university students' use of the vaccination using Ecological System Theory; and evaluated racial differences in key predictors of influenza vaccination/intention. DATA SOURCE: Sixteen engines (e.g., PsycINFO, Academic Search Premier, Science Citation Index) were used to search for cross-sectional studies (2009-2019). STUDY INCLUSION/EXCLUSION CRITERIA: PI/CO criteria were applied (U.S. students, multidimensional ecological system, influenza vaccination/intention). DATA EXTRACTION: 25 cross-sectional studies were included from the initial 810 citations. Four reviewers performed the cross-checking. DATA SYNTHESIS AND RESULTS: Higher SES (e.g., education, vaccine affordability, healthcare resource) were positively associated with vaccination/intention. Under micro levels, both internal factors (e.g., positive beliefs, perceptions, attitudes) and external factors (e.g., supports/recommendations from physicians, families or peers, information, engagement in campus activities) enhanced influenza vaccination/intention of students. Meso level factors (private university, dorm-residence, or student housing) also influenced influenza vaccination/intention. Despite limited information on the effects of race on influenza vaccination, the current study synthesized the racial variances in vaccination behaviors of students. CONCLUSIONS: Enhancing positive beliefs, perceptions, or attitudes toward influenza vaccination with students is critical. Information about the safety and effectiveness of vaccination could be provided for students through official media, medical sources/physicians, campaigns, or internet websites. Family-to-student or peer-to-peer awareness campaigns could facilitate the vaccination of students.

Sex and racial/ethnic differences in the prevalence of overweight and obesity among U.S. college students, 2011-2015.

OBJECTIVE: To investigate sex and racial/ethnic differences in overweight and obesity in college students. Participants: A nationally representative sample of 319,342 U.S. college students (mean age = 20.4 years; 67.7% female) from Fall 2011 to Spring 2015. Methods: A secondary data analysis of multi-year cross-sectional data was performed. Multiple logistic regression was used to examine factors (e.g. cumulative grade average, year in school, and living place) associated with overweight and obesity determined from BMI calculated by self-reported height and weight. Results: The prevalence of overweight and obesity was significantly higher for both sexes in Spring 2015 than in Fall 2011. Significant differences were found in overweight and obesity by sex and race/ethnicity. Higher adjusted odds ratios for overweight and obesity were observed for men, blacks, and Hispanics (compared to whites). Asians had the lowest adjusted odds of overweight and obesity. Conclusions: Intervention strategies for the prevention and management of overweight and obesity in U.S. college students should consider sex and racial/ethnic inequalities.

Relationship between sleep and obesity among U.S. and South Korean college students.

BACKGROUND: Little is known about the relationship between sleep and obesity in young adults, particularly college students. This study examined the relationship between sleep (i.e., sleep duration and quality) and obesity in a large and diverse binational sample of college students. METHODS: Analyses were based on a 40-item paper survey from 2016/2017 to 2017/2018 academic years, with a 72% response rate. The samples were 1578 college students aged 18-25 years from five universities (two in the U.S. and three in South Korea). Weight and height were measured objectively; other measures (e.g., health behaviors) were self-reported. Multinomial logistic regression was used to assess the association between sleep duration and independent variables (race/nationality, gender, and BMI). Poisson regression was used to examine the relationship between sleep quality and independent variables. RESULTS: Overall, blacks had a higher adjusted odds ratio (AOR) of short sleep (< 7 h/night) than whites (AOR = 1.74, P < .01); overweight participants had a higher AOR of short sleep than normal weight participants (AOR = 1.52, P < .01); and obese participants had a higher AORs of both short and long sleep (> 9 h/night) (AOR = 1.67, P < .01; AOR = 1.79, P < .05, respectively). Among men, being black, overweight, and obesity were associated with short sleep (P < .05), whereas only obesity was related to short sleep among women (P < .05). In analyses stratified by race and nationality, overweight and obesity were related to short sleep among blacks only (P < .05). Overall, sleep quality (getting enough sleep to feel rested in the morning in the past 7 days) was worse in blacks and South Koreans than whites (P < .05), worse in women than men (P < .05), and worse in participants with obesity than normal weight participants (P < .05). CONCLUSIONS: Obesity was associated with both short (< 7 h/night) and long sleep duration (> 9 h/night) and poor sleep quality among all participants. In comparison with whites, blacks were more like to have short sleep, and blacks and South Koreans had worse sleep quality. Further investigations using a larger sample of college students in multiple countries may be helpful to identify target populations who are at a greater risk of obesity and sleep problems.

Is waist circumference ≥102/88cm better than body mass index ≥30 to predict hypertension and diabetes development regardless of gender, age group, and race/ethnicity? Meta-analysis.

Between body mass index (BMI) ≥30 and waist circumference (WC) ≥102/88cm, we investigated which of the two measures is a better predictor of two of the most common chronic diseases - diabetes mellitus and hypertension while also examining differential association by gender, age group, and race/ethnicity. Meta-analysis was conducted for all longitudinal studies with at least 12months of follow-up published up to April 2015. Ratio of relative risk (rRR) and relative risk of diseases were computed and compared by baseline obesity measurement. The final sample included 23 longitudinal observation studies involving 62 study arms with 259,200 individuals. WC≥102/88cm was a better predictor than BMI≥30 for development of diabetes (rRR=0.81, 95% CI=0.68-0.96), but not for hypertension (rRR=0.92, 95% CI=0.80-1.06). Subgroup analyses showed WC≥102/88cm was a better predictor for diabetes in women than men, and for ages 60 and older than other ages. Only WC≥102/88cm, not BMI≥30, predicted development of hypertension among Hispanic/Latinos. Neither BMI≥30 nor WC≥102/88cm were significant predictors of hypertension when age group was controlled. Central obesity may be a more serious risk factor for diabetes development in women and for older ages. The predictive power of BMI≥30 or WC≥102/88cm in hypertension development should not be emphasized as either could mask the effect of age.

Smoking among East Asian college students: prevalence and correlates.

OBJECTIVES: To compare the prevalence and correlates of cigarette smoking among East Asian college students. METHODS: Data were collected from college students (N=16,558) in China, Hong Kong, Malaysia, Singapore, South Korea, and Taiwan (response rate: 78%). RESULTS: Religion was independently associated with college students' smoking in China (adjusted odds ratio [AOR] = 1.82) and South Korea (AOR = 0.80). Being a heavy drinker and having a higher exposure to secondhand smoke were associated with higher smoking rates (Ps < .001). CONCLUSIONS: The East Asian economies show a varied prevalence of college smoking but a similar pattern of relationship with its correlates.