BMI and perceived weight on suicide attempts in Korean adolescents: findings from the Korea Youth Risk Behavior Survey (KYRBS) 2020 to 2021
BMC Public Health volume 23, Article number: 1107 (2023)
Suicide is a leading cause of death in South Korea (hereafter ‘Korea’), and there is evidence that body weight and perceived weight affecting suicide have a significant effect on suicidal behavior in adolescence. This study investigated the association between body mass index (BMI), perceived weight, and suicide attempts in adolescents.
We included nationally representative data for a total of 106,320 students in our final analysis. We calculated and stratified BMI (underweight, normal weight, overweight) to determine the correlation between BMI and suicide attempts. We stratified the participants into three groups (perceived as underweight, normal weight, and overweight) for subjective body weight perception to analyze the relationship between subjective body weight perception and suicide attempts. We further analyzed the combination of BMI and subjective body weight perception to determine the relationship between suicide attempts and distorted subjective weight perception.
Compared with perceiving oneself as having a normal weight, the odds ratios (ORs) for suicide attempts were significantly increased in the group perceiving themselves as overweight. In addition, those who perceived themselves as overweight but were underweight according to their BMI were at significantly increased risk of suicide attempts relative to those who perceived themselves as about the right weight.
There was a significant association with suicide attempts in the underweight and perceived overweight group. This shows the importance of combining BMI and perceived weight when examining the relationship between weight and suicide attempts in adolescents.
The suicide rate in Korea ranks first among Organization for Economic Cooperation and Development (OECD) countries at 25.4 per 100,000 persons . Suicide accounted for 1.3% of global deaths in 2019, and more than 700,000 people die by suicide every year, the World Health Organization (WHO) reports . The suicide rate trend in Korea is growing more serious, and the suicide rate among young people is increasing faster than that of the older adult population . Suicide is the leading cause of death in Korea, especially among those aged 10 to 39 years . The risk factors for suicide include socioeconomic status, demographic factors, urbanicity, general health behaviors, and other environmental factors. Among the various factors that influence suicide, obesity and weight control may have a significant impact on suicidal behavior in adolescence, and studies on their association are ongoing. Particularly, several studies have shown that perceived weight, weight status, body mass index (BMI), and body satisfaction are important risk factors for suicidal behavior in adolescents . Previous studies have also demonstrated that BMI and perceived weight are equally related to suicidal behavior [4,5,6,7,8]. In another study, people who perceived themselves as overweight had a statistically significant suicide attempt, although they were not overweight according to their BMI . Weight is related to mental health and quality of life, and an abnormal or excessive fat in particular can harm mental health and quality of life [9, 10]. Some people may believe that they will be more likely to attempt suicide if they are obese, and some papers claim this as well . Obese individuals may also have poor mental health because obesity is stigmatized [12,13,14]. However, many studies have found the opposite, showing fewer suicides and suicide attempts in people with obesity [15,16,17,18,19,20,21,22,23,24]. There is further evidence that underweight people have a higher risk of suicide and suicide attempts than those of normal weight [15, 16, 19, 21,22,23,24,25]. Previous studies have shown diverse suicide-related outcomes with regard to obesity. Some of the studies were cross-sectional [5, 7], some were based on small samples , and some showed different results according to gender  or age [5,6,7].
Many existing studies have examined the relationship between obesity and suicide [4, 15, 16] or perceived weight and suicide [5, 26, 27]. When individuals perceive themselves as obese, they become afraid of negative social sentiment as the stigma of obesity has been socially internalized; therefore, perceived weight is important . These negative psychological effects can cause suffering, which may intensify suicidal thoughts, suicide plans, and even suicide attempts . Therefore, studying the relationship between suicide and obesity according to the BMI and perceived weight is necessary because both may cause negative psychological effects. However, few have examined the association between suicide attempts and the combination of body mass index (BMI) and subjective body weight perception. Therefore, the purpose of this study was to examine this association in adolescents using data from the national population-based Korea Youth Risk Behavior Survey (KYRBS).
Materials and methods
Data source and study population
This study was based on data collected by the KYRBS from 2020 to 2021. The KYRBS is a cross-sectional survey that has been conducted annually since 2005 by the Korea Centers for Disease Control and Prevention (CDC). The KYRBS is an ongoing national survey that assesses health-risk behaviors among middle- and high-school students, monitors progress toward achieving the national health objectives of Korea’s National Health Plan, and provides data for the development and evaluation of school health policies in South Korea. The KYRBS provides national data that identify the current state and trends in health behaviors of adolescents in Korea, including questions about smoking, drinking, obesity, diet, and physical activity. The data also included information on mental health areas such as obesity status (including perceived weight) and suicide attempts; therefore, this data was selected and investigated in this study. In 2020–2021, 109,796 students (54,948 in 2020 and 54,848 in 2021) from 800 schools (400 middle schools and 400 high schools) were surveyed. This study included 106,320 subjects, excluding those who were not suitable (Fig. 1).
Body mass index
Anthropometric data, including height and weight, were obtained by the KYRBS, and BMI was calculated by dividing each individual’s weight (kg) by their squared height (m2). This study followed the criteria set out in the 2007 Korean Children and Adolescents Standard Growth Chart to classify individuals as underweight (BMI < 5th percentile), normal weight (5th percentile ≤ BMI < 85th percentile), or overweight (BMI ≥ 85th percentile) . In this study, the values calculated according to the adolescent guidelines were BMI < 16.4 for underweight, 16.4 ≤ BMI < 25.5 for normal weight, and BMI ≥ 25.5 for overweight.
Subjective body weight perception
The survey evaluated self-perceived weight using the topic, “How do you describe your body type?” respondents answered on a scale of 1 to 5 points with a median of 3. This study used a three-point scale consisting of perceived underweight, perceived normal weight, and perceived overweight. Those who responded “very skinny” or “slightly skinny” were measured as perceived underweight, “very fat” or “slightly fat” as perceived overweight, and the midpoint as perceived normal weight.
The KYRBS asked participants about suicide attempts: “Have you attempted suicide in the past 12 months?” Respondents could answer “yes” or “no.” Suicide attempts were coded as “0” for never attempted suicide or “1” for any suicide attempt.
Because the KYRBS has a structured survey design, the analysis was performed using the SAS PROC SURVEY method, including weights, hierarchical variables, and cluster variables. We used the Student’s t-test for continuous variables and Fisher’s exact test for categorical variables to test the differences in baseline characteristics between students who attempted suicide and those who did not. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) to compare suicide attempts according to BMI and subjective body weight perception. The analysis was stratified into three groups according to BMI (underweight, normal weight, overweight) and subjective body weight perception status (perceived underweight, perceived normal weight, perceived overweight). Two separate models were evaluated. The first model was adjusted for sex (male or female) and class (middle- or high-school). The second model was further adjusted for sex, class, parental education level (lower than middle school, high school, college, and higher), smoking status (smoker or non-smoker), alcohol consumption (drinker or non-drinker), drug use (yes or no), depressive symptoms (yes or no), and self-perceived overweight (yes or no).
We also investigated the combined effects of BMI and subjective body weight perception on suicide attempts. Combined effects represent the combination of BMI and subjective body weight perception. The following nine groups were defined according to BMI and subjective body weight perception: 1) Underweight/Perceived Underweight, 2) Underweight/Perceived Normal weight, 3) Underweight/Perceived Overweight, 4) Normal weight/Perceived Underweight, 5) Normal weight/Perceived Normal weight, 6) Normal weight/Perceived Overweight, 7) Overweight/Perceived Underweight, 8) Overweight/Perceived Normal weight, 9) Overweight/Perceived Overweight.
All statistical analyses were performed using SAS version 9.4 (SAS Institute, Cary, NC, USA), and p-values < 0.05 were considered to indicate statistical significance.
Table 1 displays the baseline characteristics of all students from KYRBS 2020–2021. The average age of the study subjects was 15.10 ± 1.75 years, and 48.1% were female. Suicide attempts was identified in 2,178 of the 106,320 subjects, representing a 2.0% prevalence of suicide attempts. Compared with students without suicide attempts, those with suicide attempts had depressive symptoms and parents with lower educational attainment, and were more likely to be female, perceive themselves as overweight, non-smokers, drinkers of alcohol, and drug users (All for p < 0.0001).
Table 2 shows the calculated ORs and 95% CIs for suicide attempts based on BMI and subjective body weight perception. In subgroups stratified by BMI categories, being underweight was significantly associated with increased odds of having a suicide attempt compared with the normal weight group (adjusted OR = 1.31, 95% CI:1.06–1.63) after adjusting for covariates (model 2). In subgroups stratified by subjective perception of body weight categories, compared with those who perceived themselves as having a normal weight, the ORs for suicide attempts were significantly increased in those who perceived themselves as underweight (adjusted OR = 1.14, 95% CI:1.00–1.29) and overweight (adjusted OR = 1.31, 95% CI:1.18–1.45) (Model 1). After adjusting for covariates in Model 2, these findings were significant in the perceived overweight group (adjusted OR = 1.16, 95% CI: 1.04–1.29) but not in the perceived underweight group.
Table 3 shows the association between suicide attempts and the combination of obesity status and subjective body weight perception. Using “about the right weight” as a reference, underweight students were more likely to perceive themselves as underweight, normal-weight students were more likely to perceive themselves as having a normal weight, and overweight students were more likely to perceive themselves as overweight. The proportions of students who correctly perceived their body weight status were 89.8% in the underweight group, 44.3% in the normal weight group, and 95.6% in the overweight group. We observed that those who perceived themselves as overweight but were underweight or a normal weight according to their BMI were at greater risk of suicide attempts than students who perceived themselves as approximately the right weight. In contrast, students who were overweight according to their BMI had a lower risk of suicide attempts than those who correctly perceived their weight, although the difference was not statistically significant. In particular, those who perceived themselves as overweight but were underweight according to their BMI were at significantly increased risk of suicide attempts (adjusted OR = 5.95, 95% CI: 1.12–31.75) relative to those who perceived themselves as approximately the right weight.
This study investigated the association between suicide attempts and the combination of BMI and subjective body weight perception in Korean adolescents using nationwide KYRBS data. Regarding the BMI and suicide attempts, the underweight group tended to make more suicide attempts than the normal weight group; regarding the subjective body weight perception and suicide attempts, the overweight group tended to make more suicide attempts than the normal weight group.
Regarding the combination of BMI and subjective body weight perception, individuals who were underweight and perceived themselves as overweight tended to make more suicide attempts than individuals who were underweight and perceived themselves as underweight. The results were adjusted for demographic variables, including age, sex, alcohol consumption, smoking, drug use, weight self-perception, parents’ educational level, and depressive symptoms.
Previous studies have indicated a relationship between obesity status and mental health, but the direction of the results varies. In one cohort study, those who were underweight showed a lower tendency for suicide ideation [15, 17]. A study of the US National Health Interview Survey indicated a reversed association between body weight and suicide . A cohort study of Swedish men similarly showed that suicide attempts decreased as BMI increased [19, 24]. In the Korean Cancer Prevention Study, those with biological cardiovascular disease risk factors, including being underweight, tended to have a higher suicide mortality rate . The Taiwanese and British adults cohort study and the Veterans Affairs health system in the US have shown similar results [11, 22, 23, 25].
Several studies have produced results similar to those of our study regarding self-perception of being overweight and suicidal ideation . The risk of suicidal ideation, suicide plans, or suicide attempts, which define suicidality, related to the self-perception of being overweight increased from 5.7 percentage points in 1999–2001 to 10.1 points in 2015–2017 according to the Youth Risk Behavior Survey among US adolescents in grades 9–12 . Furthermore, in a systematic review and meta-analysis, those with a self-perception of being overweight tended to have poor mental health, including depression, attempted suicide, depressive symptoms, and suicidal ideation .
The US Youth Risk Behavior Survey presented a similar relationship between suicide attempts and the combination of obesity status and subjective body weight perception . The results showed that those with a self-perception of being overweight while not being overweight tended to have more suicide attempts . These results support the fact that a statistically significant number of suicide attempts were made when there was a difference between individuals’ actual and perceived weight, such as when a person perceived that they were overweight despite being underweight as in our thesis results [4, 31].
Furthermore, adolescent suicide attempts may be influenced by the gap between socially constructed body image—which can result from social norms, stigma, and influence—and the definition and reality of obesity [4, 31]. Self-perceived abnormal weight (i.e., overweight or underweight) in adolescence is strongly associated with negative psychiatric conditions, such as suicidal behavior [26, 27, 32,33,34,35]. These results show the causal relationship between self-perceived weight and suicidal behavior .
This study had several limitations. First, it followed a cross-sectional design; therefore, it is difficult to confirm a causal relationship. Moreover, reporting biases are possible because respondents’ height and weight were self-reported data. Second, our study had some reliability limitations in our results. Our results showed a wide confidence interval owing to the small sample size. Finally, this study only included students who were attending school, so it does not reflect the results of adolescents who did not attend school.
Despite these limitations, this study presents a new perspective by examining the relationship between adolescent BMI and suicide attempts alone and in combination with self-perceived weight from Korean national data. Apart from one’s actual and perceived weight, one’s desire to lose weight will be an important variable in understanding suicide attempts in future research.
This study showed the relationship between suicide attempts and the combination of BMI and subjective body weight perception among Korean adolescents using data from the nationwide KYRBS. There was a significant relationship between the underweight/perceived-overweight group and suicide attempts. This study provides a new perspective on the relationship between weight and suicide attempts in adolescents by combining BMI and self-perceived weight.
Availability of data and materials
Publicly available datasets were analyzed in this study. These data can be found at https://www.kdca.go.kr/yhs/.
OECD. Suicide rates (indicator). 2022.
World Health Organization. Suicide in the world: global health estimates. 2019.
Jang H, Lee W, Kim YO, Kim H. Suicide rate and social environment characteristics in South Korea: the roles of socioeconomic, demographic, urbanicity, general health behaviors, and other environmental factors on suicide rate. BMC Public Health. 2022;22(1):410.
Swahn MH, Reynolds MR, Tice M, Miranda-Pierangeli MC, Jones CR, Jones IR. Perceived overweight, BMI, and risk for suicide attempts: findings from the 2007 youth risk behavior survey. J Adolesc Health. 2009;45(3):292–5.
Eaton DK, Lowry R, Brener ND, Galuska DA, Crosby AE. Associations of body mass index and perceived weight with suicide ideation and suicide attempts among US high school students. Arch Pediatr Adolesc Med. 2005;159(6):513–9.
Crow S, Eisenberg ME, Story M, Neumark-Sztainer D. Are body dissatisfaction, eating disturbance, and body mass index predictors of suicidal behavior in adolescents? A longitudinal study. J Consult Clin Psychol. 2008;76(5):887–92.
Crow S, Eisenberg ME, Story M, Neumark-Sztainer D. Suicidal behavior in adolescents: relationship to weight status, weight control behaviors, and body dissatisfaction. Int J Eat Disord. 2008;41(1):82–7.
Whetstone LM, Morrissey SL, Cummings DM. Children at risk: the association between perceived weight status and suicidal thoughts and attempts in middle school youth. J Sch Health. 2007;77(2):59–66.
McLaren L, Beck CA, Patten SB, Fick GH, Adair CE. The relationship between body mass index and mental health. A population-based study of the effects of the definition of mental health. Soc Psychiatry Psychiatr Epidemiol. 2008;43(1):63–71.
Audureau E, Pouchot J, Coste J. Gender-related differential effects of obesity on health-related quality of life via obesity-related comorbidities: a mediation analysis of a French nationwide survey. Circ Cardiovasc Qual Outcomes. 2016;9(3):246–56.
Geulayov G, Ferrey A, Hawton K, Hermon C, Reeves GK, Green J, Beral V, Floud S. Million Women Study C: Body mass index in midlife and risk of attempted suicide and suicide: prospective study of 1 million UK women. Psychol Med. 2019;49(13):2279–86.
Wang SS, Brownell KD, Wadden TA. The influence of the stigma of obesity on overweight individuals. Int J Obes Relat Metab Disord. 2004;28(10):1333–7.
Seacat JD, Dougal SC, Roy D. A daily diary assessment of female weight stigmatization. J Health Psychol. 2016;21(2):228–40.
Lillis J, Levin ME, Hayes SC. Exploring the relationship between body mass index and health-related quality of life: a pilot study of the impact of weight self-stigma and experiential avoidance. J Health Psychol. 2011;16(5):722–7.
Magnusson PK, Rasmussen F, Lawlor DA, Tynelius P, Gunnell D. Association of body mass index with suicide mortality: a prospective cohort study of more than one million men. Am J Epidemiol. 2006;163(1):1–8.
Kaplan MS, McFarland BH, Huguet N. The relationship of body weight to suicide risk among men and women: results from the US National Health Interview Survey Linked Mortality File. J Nerv Ment Dis. 2007;195(11):948–51.
Mukamal KJ, Kawachi I, Miller M, Rimm EB. Body mass index and risk of suicide among men. Arch Intern Med. 2007;167(5):468–75.
Bjerkeset O, Romundstad P, Evans J, Gunnell D. Association of adult body mass index and height with anxiety, depression, and suicide in the general population: the HUNT study. Am J Epidemiol. 2008;167(2):193–202.
Batty GD, Whitley E, Kivimaki M, Tynelius P, Rasmussen F. Body mass index and attempted suicide: Cohort study of 1,133,019 Swedish men. Am J Epidemiol. 2010;172(8):890–9.
Mukamal KJ, Miller M. Invited commentary: Body mass index and suicide–untangling an unlikely association. Am J Epidemiol. 2010;172(8):900–4.
Jee SH, Kivimaki M, Kang HC, Park IS, Samet JM, Batty GD. Cardiovascular disease risk factors in relation to suicide mortality in Asia: prospective cohort study of over one million Korean men and women. Eur Heart J. 2011;32(22):2773–80.
Gao S, Juhaeri J, Reshef S, Dai WS. Association between body mass index and suicide, and suicide attempt among British adults: the health improvement network database. Obesity (Silver Spring). 2013;21(3):E334-342.
McCarthy JF, Ilgen MA, Austin K, Blow FC, Katz IR. Associations between body mass index and suicide in the veterans affairs health system. Obesity (Silver Spring). 2014;22(1):269–76.
Sorberg A, Gunnell D, Falkstedt D, Allebeck P, Aberg M, Hemmingsson T. Body mass index in young adulthood and suicidal behavior up to age 59 in a cohort of Swedish men. PLoS One. 2014;9(7):e101213.
Chang SS, Wen CP, Tsai MK, Lawlor DA, Yang YC, Gunnell D. Adiposity, its related biologic risk factors, and suicide: a cohort study of 542,088 Taiwanese adults. Am J Epidemiol. 2012;175(8):804–15.
Dukes RL, Lorch B. The effects of school, family, self-concept, and deviant behaviour on adolescent suicide ideation. J Adolesc. 1989;12(3):239–51.
Stein D, Orbach I, Shani-Sela M, Har-Even D, Yaruslasky A, Roth D, Meged S, Apter A. Suicidal tendencies and body image and experience in anorexia nervosa and suicidal female adolescent inpatients. Psychother Psychosom. 2003;72(1):16–25.
Daly M, Robinson E, Sutin AR. Perceived overweight and suicidality among US adolescents from 1999 to 2017. Int J Obes (Lond). 2020;44(10):2075–9.
Korea Center for Disease Control and Prevention, The Korean Pediatric Society, The Committee for the Development of Growth Standard for Korean Children and Adolescents. 2007 Korean children and adolescents growth standard (commentary for the development of 2007 growth chart). Government report online. Seoul; 2007.
Haynes A, Kersbergen I, Sutin A, Daly M, Robinson E. Does perceived overweight increase risk of depressive symptoms and suicidality beyond objective weight status? A systematic review and meta-analysis. Clin Psychol Rev. 2019;73:101753.
Muennig P. The body politic: the relationship between stigma and obesity-associated disease. BMC Public Health. 2008;8:128.
Orbach I, Lotem-Peleg M, Kedem P. Attitudes toward the body in suicidal, depressed, and normal adolescents. Suicide Life Threat Behav. 1995;25(2):211–21.
Page RM, Allen O. Adolescent perceptions of body weight and weight satisfaction. Percept Mot Skills. 1995;81(1):81–2.
Dietz WH. Health consequences of obesity in youth: childhood predictors of adult disease. Pediatrics. 1998;101(3 Pt 2):518–25.
Pritchard ME, King SL, Czajka-Narins DM. Adolescent body mass indices and self-perception. Adolescence. 1997;32(128):863–80.
This research was supported by a National Cancer Center grant funded by the Korean government, the Republic of Korea [NCC- 2210861-1]. In addition, we would like to thank all respondents who participated in the KYRBS.
The authors have nothing to disclose.
This research was supported by a National Cancer Center grant funded by the Korean government, the Republic of Korea [NCC- 2210861–2].
Ethics approval and consent to participate
This study analyzed secondary data and was approved by the Institutional Review Board of the Korea CDC (2014-06EXP-02-P-A). This study meets the Helsinki Declaration based ethical principles for medical research involving human subjects.
Consent for publication
The authors declare no competing interests.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Kim, B., Kim, HS., Park, S. et al. BMI and perceived weight on suicide attempts in Korean adolescents: findings from the Korea Youth Risk Behavior Survey (KYRBS) 2020 to 2021. BMC Public Health 23, 1107 (2023). https://doi.org/10.1186/s12889-023-16058-z