Measuring the precise effect of eating out on calorie intake: The case of Korea

<b>Background:</b> Estimating the actual impact of eating out on calorie intake poses challenges due to the potential endogeneity of eating out. Controlling for endogeneity is essential to obtain more precise estimates. <b>Aim:</b> This study estimates the effect of eating out on calorie intake, specifically focusing on dinner among the three daily meals. <b>Methods:</b> The endogenous treatment effect model is employed, utilizing restricted-access data from the 2017 to 2020 Korea National Health and Nutrition Examination Survey. To aid model identification, daily precipitation is used as an instrumental variable influencing the decision to eat dinner out. <b>Results:</b> Eating dinner out results in an additional intake of 388.39 Kcal compared to eating at home, whereas the model that does not control for the endogeneity estimates a 261 Kcal increase. The increase in calorie intake from eating dinner out varies significantly depending on individual characteristics. <b>Conclusion:</b> Eating out leads to a substantial amount of calorie intake. Managing the frequency of eating out at a reasonable level could play a crucial role in preventing obesity.