The consumption of food away from home in Korea has significantly increased over past decades.1 Contributing factors to increasing frequency of food away from home include reduced average family size, westernized dietary patterns, higher income, and an increasing number of working women.123 In America, the dining-out sector already reached about 25% of total food spending in 1970 with around 40% of food expenditure spent on food obtained away from home.4 Although the percentage of food expenditure per household in Korea has continuously decreased, the proportion of food budgets spent on food away from home has increased more than 2-fold from 20% in 1990 to 46.6% in 2011.5 According to reported data from the 2011 Korea National Health and Nutrition Examination Survey (KNHANES), over 25% of respondents consumed away-from-home foods more than once per day.56 For children and adolescents in particular, increased consumption of food away from home may negatively affect nutritional quality of their diets. A number of studies have reported that children who eat out have higher energy intake and lower dietary quality compared with those who do not.789 Lin et al.4 reported that away-from-home foods consumed by children have higher contents of fat, saturated fat, and sodium and less fiber and calcium than foods from home. A number of studies have shown that the increasing prevalence of childhood obesity is closely related with consumption of food eaten away from home.49 O'Dwyer et al.10 also examined the contribution of fat to energy as well as the contributions of various food groups consumed at home or away from home to fat in adults from Ireland. They found that the contribution rate of fat to energy was higher than the recommended value for foods consumed away from home, and numerous food groups prepared away from home contributed to fat intake. A study on fast food consumption patterns among elementary and high school students of Busan city in Korea reported that consumption frequencies of fast food once or twice per month were 38.5% in elementary and 40.5% in high school students. In addition, this study showed that the reasons for consuming fast food are linked to palatable taste, low price, and convenience.11 In 2005, the prevalence of obesity in children and adolescents was doubled compared to that in 1997.1213 Heo et al.14 reported that the percentages of obesity among children 2 to 18 yr of age were 13.9% in 2008 and 11.4% in 2009 based on the Korea National Health and Nutrition Examination Survey (KNHANES), whereas percentages were 8.1% in 2008 and 8.2% in 2009 based on the Korean Youth Risk Behavior Web-based Survey (KYRBWS). Childhood obesity is a serious public health problem in developing as well as developed countries.15 It is associated with various chronic diseases such as diabetes, high blood pressure and cholesterol, and metabolic syndrome. Moreover, these diseases might increase risk of related health problems in adult life.16 Therefore, the management and prevention of childhood obesity is an important objective of public health. This study aimed to examine the dietary life by frequency of food away from home among children and adolescents aged 7 to 18 yr using data from the 5th (2010~2012) KNHANES.

This study examined the consumption of food away from home as well as food and nutrient intakes of children and adolescents aged 7 to 18 yr based on the 5th (2010~2012) KNHANES. To accomplish this study, the subjects were classified two groups which were < 1/day eating-out frequency and ≥ 1/day eating-out frequency groups. With increasing age, the ratio of subjects who ate out more than once per day increased. On the contrary, the previous studies based on the adults aged over 19 62627 reported that the younger people consumed food away from home more than the older age people did. These results were thought that the consumption rate of food away from home increased with getting older from children to adolescents and this leads to increase that of food away from home in the twenties.

This study showed that the percentage of children and adolescents who skipped breakfast showed 19%. Individuals who ate out more than once per day showed higher consumption of energy and sodium than those who ate out less than once per day. Although individuals who ate three meals per day still constituted the highest percentage of subjects, the percentage of children and adolescents who skipped breakfast was fairly high (19%). Yeoh et al.21 reported that 17% of 1,600 children aged 7 to 18 yr skipped breakfast based on data from the 2001 National Health and Nutrition Survey. They also found that the rate of skipping breakfast in older children was higher than that in younger ones. The reasons for skipping breakfast were mainly associated with time constraints and not feeling hungry in the morning.28 Intake of an “adequate” breakfast, especially for adolescents, is a very important contributor to physical and mental growth as well as academic achievement. 212930 Several studies in children and adolescents showed that individuals who regularly skipped breakfast are associated with obesity development.31323334 Since skipping breakfast is an important contributor to higher levels of hunger later, it can lead to overconsumption of high fat and energy-dense foods.3536

In the result of this study, the percentage of individuals who consumed snacks was 94.2%. In the United States, the number of snacks consumed in adolescents 12 to 18 yr increased from 1.6 per day in 1977 to 1.97 snacks in 1996.3738 For nutrient quality of snacks, calcium density decreased while energy density and energy percentage from fat increased compared with non-snacking occasions.37 In this study, approximately 70% of children ate out five to six times per week, followed by 17.5% who ate out once per day and 12.1% who ate out twice per day. A study from 2003 analyzed the eating-out behavior patterns of 1,487 adolescents aged 15 and 17 yr. Regarding frequency of eating-out, 62.7% of respondents reported a frequency of one to two times per week, whereas 3.5% reported a frequency of more than five times per week.39 This result shows that the frequency of away-from-home eating dramatically increased in children and adolescents from 2003 to 2012. Regarding frequency of eating-out among age groups, the percentage of adolescents aged 16 to 18 yr who ate out more than once per day was 55.9%, followed by 27.4% in adolescents aged 13 to 15 yr and 14.7% in children aged 7 to 12 yr. This result demonstrates that older adolescents ate out more frequently than younger children. These results have been thought to come from various factors, including increased time spent outside home for school and private educational institutes, more social gatherings with peers, and increased access to fast food outlets and restaurants.

Kim et al.40 examined trends in consumption of unhealthy foods by socioeconomic position and determined the effects of the government's nutritional policies among adolescents. They observed an apparent decline in unhealthy food intakes according to the nutritional polices the government implemented. The subjects who ate out more than once per day were significantly associated with higher total and plant food intakes than those who ate out less than once per day. Regarding nutrient intakes, the more frequent eatingout group was associated with higher energy, carbohydrate, protein, fat, and sodium intakes than the other group. Some data from the United States Department of Agriculture (USDA) also suggested that away-from-home foods may contain higher energy and fat contents than foods from home.4 Especially, boys who consumed more food away from home had the highest caloric intake among all groups. Although children and adolescents need high energy and nutrient intakes for growth and development compared with other age groups, imbalance between energy intake and energy expenditure in relation to away-from-home foods may contribute to obesity development and chronic nutrition-related diseases.38 Kleiser et al.41 suggested that high intakes of energy-dense foods and beverages are significantly associated with overweight and obesity status among children and adolescents. A comparison of nutritional quality between foods at home versus away from home in 1977~2008 determined an increase in intake of away-fromhome foods from 17.7% in 1977~78 to 31.6% in 2005.42 The World Health Organization (WHO) recommends that sodium intake not exceed 2,000 mg per day.25 However, children and adolescents in this study consumed an average of 3,934.0 mg per day, which is almost two times higher than the recommended limit. All subjects who ate out more than once per day showed considerably higher sodium intakes compared to those who ate out less than once per day. Food prepared away home is an important contributor to overconsumption of sodium. Lin et al.4 found that males aged 12 to 39 yr had higher sodium intake than females since they tended to eat more than women. They also observed that foods consumed from restaurants had higher densities of cholesterol and sodium than those from fast food outlets and school. Lin et al.42 reported that Americans 2 yr of age and older had an average sodium intake per day of 3,085 mg during 2005~2008, compared with the recommended limit of less than 2,300 mg/day. The USDA42 reported that food prepared away from home constitutes 41% of food spending and 32% of caloric intake in 2008. Food away from home has become a regular dietary behavior for most Koreans due to the prevalence of twoearner households, more single households and more restaurants and fast-food establishments. Increased consumption of food away from home has increased caloric intake and lowered nutritional quality in both adults and children.3843 Unhealthy dietary patterns and overconsumption of foods away from home, low meal frequency, skipping breakfast, and consumption of more sugar-sweetened beverages in children and adolescents might be associated with obesity development and chronic nutrition-related diseases.38 Meanwhile, 24-h dietary recalls based on 1-day recall data are generally conducted through in-person interviews by trained dietary staff. A single measurement in a 24-h dietary recall survey cannot account for day-to-day and within-person variations nor represent general dietary patterns of the subjects.4445 Nevertheless, use of a single 24-h recall for measurements could be generalized to the Korean population to analyze average intake in a large nationally representative sample.45 Mancino et al.16 reported that older children consume 50% more food prepared outside the home than younger ones. Our findings also show that individuals aged 16 to 18 yr who ate out more than once per day consumed more total food and nutrients among all age groups. This result shows that older children and adolescents typically have more chances to make their own food choices than younger children since they can spend money on their own, have more time with friends, and have more freedom.16

Based on the findings of this study, 30% of school-aged children and adolescents consumed food away from home more than once per day, and older children from higher income households more frequently ate out than other children. Individuals who ate out more than once per day showed higher consumption of energy and sodium than those who ate out less than once per day. Excessive intake of energy and sodium are associated with obesity, high blood pressure, diabetes, and obesity-related diseases, suggesting education is needed to improve child nutrition and prevent obesity.

This study has some limitations. First, the KNHANES only surveyed limited socio-demographic variables. Therefore, comparative analysis of various demographic, lifestyle, and behavioral variables was not conducted. Second, we could not include institutional and commercial results in eating-out frequency since eating-out frequency in the KNHANES data did not include institutional foodservice or commercial eating-out. Therefore, addition of diverse eating-out materials to the KNHANES is necessary for future research.

This study was to investigate the dietary quality of food away from home among Korean children and adolescents. Thirty percent of subjects were shown to consume food away from home more than once per day, and 7~18 children and adolescents in Korea from higher income households showed a higher frequency of food away from home compared to other children. The percentage of children and adolescents cited as regularly skipping breakfast showed 19%. Individuals who ate out more than once per day resulted in higher consumption of energy and sodium than those who ate out less than once per day. For children aged 7 to 12 yr old, the intakes of nutrient and energy contribution ratio of three main nutrients(carbohydrate, protein, and fat) differed significantly between more than once and less than once eating-out frequency groups of children 7 to 12 yr. As with adolescents aged 16 to 18 yr, the intakes of carbohydrate and sodium differed significantly between significantly between more than once and less than once eating-out frequency groups. The subjects who ate out more than once per day showed higher consumption of energy and sodium than those who ate out less than once per day. Based on these results, excessive intakes of energy and sodium are associated with obesity, high blood pressure, diabetes, and obesity-related diseases. Thus, there is a need for nutritional intervention and educational efforts to improve child nutrition and prevent obesity.