Editorial Board

Obesity is a risk factor for non-communicable diseases (NCDs) among people of all ages and classified by the World Health Organization (WHO) as a disease (World Health Organization, 2020). Increasing of obesity rate for the last three decades was conditioned by different factors, for instance changing dietary habits and decreasing physical activity (Blüher, 2019). The same trend is observed in the population of South Koreans where the prevalence of obesity (body mass index [BMI] ≥ 25) among adults aged 19 years or older was 34.8% in 2016, which was higher than that in 2005 (31.3%), suggesting that over one-third of the population was obese (Korean Statistical Information Services, 2020). According to a study that analyzed treatment costs using national health insurance data from 2016, obesity-related illnesses incurred costs of approximately 7.5 billion USD, and the highest costs on healthcare service utilization were associated with obesity, and these costs are consistently trending upward (Lee, 2019).

International experience shows that national-level efforts are essential for reducing obesity. In particular, the United Kingdom and the United States are working to reduce obesity rates by actively pursuing preventative strategies and launching whole-of-government campaigns at the national level, including promoting healthy foods and improving their accessibility, encouraging physical activity through constructing suitable environments for exercise, and providing personalized obesity management for at-risk groups (Capehorn, Haslam, & Welbourn, 2016; Musingarimi, 2009; Tseng et al., 2018). Although, regional-level strategies also need to be developed due to cultural and habitual factors. Therefore, a “culture-oriented approach” that fits local lifestyles also should be considered.

Obesity is known as a result of an imbalance in energy intake and expenditure; therefore, the emphasis has been placed on either reduced food intake or increased physical activity (Kim, Kim, & Hyun, 2019). A lot of previous studies have focused on the development of education and programs pertaining to the quality and quantity of foods and exercise requirements. However, despite temporarily reduced food intake, the maintenance of a lower-calorie diet is difficult, and compliance is low (Kim, Kim, Kim, Hong, & Chang, 2013). Also, physical activity and weight have a complicated relationship, involving numerous factors, the issue of obesity has not been readily resolved despite multiple intervention programs (Tan, Dunn, Samad, & Feisul, 2011). Therefore, identifying and presenting simple weight-management “strategies” that leads to the natural long-term behavior changes is required additionally to strict behavioral change programs, such as restricting calorie intake and increasing physical activity (Kirk, Penney, McHugh, & Sharma, 2012; Munro, Bore, Munro, & Garg, 2011).

Ford and colleagues (2010) reported the effectiveness of the obesity treatment among adolescence through retraining of the eating rate for long-term behavior changes. The multiply interventions based on the longer-term weight-management have high value for evidence-based intervention in health practices (Kirk et al., 2012). In this regard, it is difficult to continuously maintain the exact number of calories through short-term calorie restrictions programs. Continuous weight-management could be achieved by changing eating habits in the way of consuming food at a slower pace.

An important role in the weight-management plays decreasing in the calory intake. The physiological studies explored the effect of the satiety signals and calorie intake, and provide evidence that the decreasing of eating rate lead to satiety with lower calorie intake (Andrade, Greene, & Melanson, 2008; Benelam, 2009; Kokkinos et al., 2010). Eating slowly facilitates satiation by allowing time for the transmission of the satiety signal to the brain, which takes approximately 20 min (Lee, 2000). Therefore, at least 20 min of mastication is needed for the brain to recognize satiety, thereby preventing overeating that is important in obesity behavioral correction (Ookuma, Yoshimatsu, Sakata, & Adachi, 2000). Considering the so-called “quickly-quickly” (bballi-bballi) culture in South Korea, this is important to consider the influence of the eating rate on obesity.

Guidelines have been proposed for the adolescent populations of certain countries; however, guidelines on dietary habits for adults are required additional development (Musingarimi, 2009; Weihrauch-Blüher et al., 2018). Also, the previous study reported gender difference in the development of obesity rate and dietary habits that shows need to develop a different approach depending on the gender (Kim & Kim, 2010; Leong, Madden, Gray, Waters, & Horwath, 2011; Yamane et al., 2014). In this study, we aimed to provide an understanding of relationships between eating rate as “cultural phenomena” on obesity among Korean male and female adults.

Obesity studies have mainly focused on weight loss methods by reducing food intake or increasing physical activity. However, bodyweight needs to be controlled throughout one’s lifetime, not only in the short-term. Therefore, weight control goals must include both weight loss and weight maintenance. It is also necessary to change perspectives related to obesity, and strategies are needed to alter behaviors by changing individual perceptions. For example, health promotion indices are lower in Gangwon Province, and this area had the worst obesity indices (29.7% in 2015 and 34.3% in 2018) in South Korea during the last 5 years (Korea Centers for Disease Control and Prevention, 2018). In this study, we examined the relationships between obesity and eating rate to find strategies that could help prevent obesity in real-life settings.

The result of our study illuminates that obesity rates were 36.5% in men and 29.9% in women, demonstrating a higher prevalence of obesity in men. Obesity prevalence was higher among those participants who spend less than 20 minutes for one meal intake. After controlling for adjustment variables, male participants with an eating rate of ≤ 20 min had a higher obesity rate. Among women, the obesity rate was higher in participants with an eating rate of ≤ 20 min and irregular mealtimes. Regardless of gender, an eating rate of ≤ 20 min was correlated with obesity that coincides with previous studies which showed similar results (Lee et al., 2013; Leong et al., 2011). Regardless, Paz-Graniel, Babio, Mendez, and Salas-Salvadó (2019) did not report a relationship between eating rate and obesity. It is important to highlight that studies on the physiological effect of the eating rate and calorie intake showed a relationship between satiation, satiety, and health behavior (Benelam, 2009; Maljaars, Peters, & Masclee, 2007; Ohkuma et al., 2015). Particularly, Andrade et al. (2008) reported that the individuals who spend more time on one meal intake have a higher level of satiety and satisfaction with food intake less weight and calories than the individuals who eat a meal within 20 minutes.

The previous study reported similar findings, particularly, Ahn, Chang, and Kim (2007) found that the mean durations of university students with obesity were significantly shorter than those with a healthy weight. In another study of university students of both genders, students in the obese group were found to have a faster eating rate than those in the healthy group (Jun et al., 2013). Besides, it was found that shorter meal durations were associated with BMI, independent of overall energy intake (Kamath & D’Souza, 2013). Those findings further indicate the relationship between a fast eating rate and obesity. Remarkably, the eating rate is impacted by South Korean “quickly–quickly” culture that permeates every aspect of the South Korean lifestyle, and meals are no exception (Kang, 2010). Despite this, according the OECD data Korean population spent more time for eating and drinking (1 hour 43 minutes) that OECD average (1 hour 31 minutes), however it can be commented more to the eating out of home (OECD, 2020).

Also, eating out of home shows the high prevalence of obesity in both genders. However previous study among Korean adults reported a significant relationship on eating-out among men (Kim et al., 2019). Previous studies reported the eating out of home influenced the anthropological changes and associated with the high-calorie intake (Bezerra, Curioni, & Sichieri, 2012; Lachat et al., 2012). Eating out of home is associated with the cultural aspect of the Korean society that choice of food is influenced by the collectivism, paternalism, and hierarchical culture (Koo & Park, 2013; Park et al., 2017).

Previous studies on middle-aged obesity showed that obese women had more irregular dietary habits and higher intakes of animal fat than did non-obese women (Lee, Oh, & Ahn, 2008; Leong et al., 2011), and irregular breakfast habits contributed greatly to obesity (Kim & Kim, 2010). Consistently, in the present study, obese women were more likely than healthy-weight women to eat irregular meals. These findings suggest that irregular meals may promote binge eating, leading to faster eating rates, and are linked to obesity. However, in Sohn and Jin (2008) study, obesity was not associated with meal regularity or eating three meals per day among women aged 20 years or older. These inconsistent findings suggest that age might be an important factor contributing to obesity.

Programs and treatments for weight control based on behavioral correction require extensive time. However, many individuals desire to reduce weight within a short time (Choi & Kim, 2011). Changing personal dietary habits do not produce rapid weight loss, although lifestyle habits for weight management play an essential role in obesity prevention and control (Phillips et al., 2013). Notably, previous studies emphasized the need to increase non-exercise activity thermogenesis (NEAT) rather than exercise (Healy et al., 2007). For instance, a study comparing energy expenditure between obese and non-obese groups found lower NEAT due to sedentary behavior, resulting in reduced overall energy expenditure, in the obese group (Levine et al., 2005). This observation supports our findings that introducing simple habits into daily life may impact obesity prevention.

Despite that our study does not aim to explore the influence of the social-demographic factors on the obesity rate, our findings contributed to previous studies were age, education level, occupation, marital status, and residence were significant factors (Malik et al., 2013; Molarius, 2003; Sobal, 2001). Middle age men were more predisposed to obesity rather than older adults, while women developed obesity with increasing age (Sobal, 2001). The prevalence of obesity was higher among women who were involved in unskilled work rather than professional workers. However, this patent is closely related to the level of education, and women with higher education might have more access and knowledge about a healthy lifestyle (Aekplakorn et al., 2014). Marital status was significant factors to develop obesity among married men, which is similar to the previous studies (Harcourt, Appleton, Clegg, & Hunter, 2020; Sobal, Rauschenbach, & Frongillo Jr, 1992). Participants from a rural area have a high risk of the obesity that those who live in an urban area that similar to the Global trends and mostly caused by lifestyle pattern (Befort, Nazir, & Perri, 2012; Cummins & Macintyre, 2006; Parks, Housemann, & Brownson, 2003).

Follow implications can be suggested based on the study findings. Intervention is a necessity for the prevention of obesity, and the health education program should direct to the modification of the cultural eating aspect of the “quickly–quickly” and the importance of the slowly eating rate (more than 20 minutes). Another intervention is necessary to address the influence of eating out of home behavior, where individual dietary preferences should be considered for weight management.

This study has several limitations. First, the study was designed as cross-sectional and focused on association between obesity and eating rate, so causal relationships between obesity and dietary behavior (such as calorie intake, composition of diet, etc.) were not evaluated. The second limitation is that we could not measure the participants’ actual heights and weights or confirm their precise meal as data was self-reported based, and the extremely obese group was lower. Third, data on the eating rate presented in this study was obtained from CHS’s participants in Gangwon province. Despite these limitations, the CHS provides large-scale research data at the local government level in South Korea using representative samples. Therefore, the relationships observed between obesity and eating rate are valid. The factors affecting obesity are considerably complex, and further studies are needed to explain the personal behaviors implicated in this study to the entire population, as well as a longitudinal study is necessary to evaluate the continuous effect of the eating rate on obesity development. Notably, this study provided valuable data and findings by including multiple factors that could be used to distinguish between individual eating rate, other dietary habits, and physical activity. Therefore, the present findings will contribute to planning future obesity management programs. Weight control requires persistent behavioral changes and motivation, and obesity programs considering these factors need to be developed in the future.

We examined the relationships between eating rate and obesity to provide evidence for obesity prevention strategies. The primary factor affecting obesity among male and female participants was an eating rate of ≤ 20 min; additionally, irregular meals were significant factors to develop obesity among female participants, and eating out of home was significant for both genders. These findings strongly suggest that obesity could be prevented by simple changes in dietary and lifestyle habits. Based on these findings, behavioral correction strategies adjusting for the eating rate should be introduced to improve the impact of existing obesity prevention and management programs. The findings in this study could be used to establish strategies for obesity prevention programs by modifying lifestyle habits. Further studies with more extensive and diverse cohorts are needed to validate our findings.