This study was aimed to examine the association between body mass index, subjective body shape, and suicidal ideation among Korean adults by age groups. Adjusted for covariates, results showed that the association between body shape categories and suicidal ideation was different by age groups.
Among young-aged adults (age 19–44), overweight-fat people were more likely to have suicidal ideation. This result is consistent with previous findings with relatively young population [22, 27–28]. According to Yazdani et al. [28], body image defects caused by obesity can have negative effects on psychological well-being. In addition, negative social gaze on obese population and life dissatisfaction can lead to depression, which is a major risk factor for suicide [27].
Among middle-aged adults (age 45–64), underweight-skinny people were more likely to have suicidal ideation. This result is similar to findings that people who are underweight or perceive themselves as skinny have worse mental health than healthyweight people [7, 11, 20, 29]. According to Coin et al. [30], malnutrition is often associated with being underweight, resulting in decreased immunity, anemia, osteoporosis, muscle loss, etc. Middle-aged adults who are susceptible to above risks have low level of health-related quality of life, which is associated with suicidal ideation [31].
Among older adults (age 65+), healthyweight-fat people were more likely to have suicidal ideation. Indeed, elderly obesity is known as a risk factor for cardiovascular disease, cancer, and mortality [32]. Therefore, if older adults perceive them as fat even though they have healthyweight, it is likely to lead to health concerns and poor quality of life, which can be associated with suicidal ideation.
Study findings suggest that not only the discrepancy between objective and subjective body perception (i.e. healthyweight-fat category), but also people out of the normal range of body weight defined by the society (i.e. underweight-skinny, overweight-fat) have suicidal risk. In other words, people expect to be belonged to the normal category, but being in abnormal category makes them frustrated and lose self-esteem. This is in line with Etcoff’s [33] finding that normal body shape is preferred over very skinny or very fat body shape.
In socio-cultural contexts, people form their own values and norms about body shapes, and individual characteristics such as self-esteem can be associated with them [34]. Nevertheless, negative views or perceptions about the body shape caused by appearance pressuresism in Korean society [35] results in negative emotional reactions such as sadness and loneliness when the desire for belonging to normal category is frustrated. And when self-esteem is hurt, people feel worthlessness and self-disappointment that it is difficult for them to have rational thoughts [35].
Another suggestion should be providing different weight programs to prevent suicidal ideation by different age groups. For young-aged and older adults who are sensitive to gaining weight, weight control programs should be implemented more effectively. Providing programs which can show how to manage healthy body shape can be helpful for middle-aged adults. In addition, these programs should go hand in hand with an effort to improve and change negative awareness on body shapes. In sum, elevating self-esteem by relieving obsessive thoughts and escaping from socio-cultural pressure about body shapes are required.
There are some limitations in this study that should be noted. First, suicidal ideation was measured with a single questionnaire, therefore the level of suicidal ideation could not be identified in detail. Second, when determining body shape categories, a sample size was very small in underweight-normal/fat group. Therefore, the results should be interpreted with caution. Lastly, the 2017 KCHS is a cross-sectional data, therefore the causal relationship could not be explored.
Although this study has several limitations, this study has strengths. First, this study investigated the relationship between body mass index, subjective body shape, and suicidal ideation among Korean adults using a nationally representative sample. Therefore, the findings from this study are generalizable. Second, studies on body shapes and suicidal ideation were often examined among adolescents or younger age groups, but this study examined this association in older age groups as well. Third, this study examined the age group differences, which could suggest tailored suicide prevention programs according to age groups.