Background: Previous studies have shown a close relationship between skipping breakfast and nutritional deficiency. However, the impact of regular eating, including lunch and dinner, has not been studied well. We explored the correlation between regularity and frequency of daily meals and nutritional status.

Methods: We analyzed Korea National Health and Nutrition Examination Surveys between 2016 and 2018. A total of 7,725 adults aged 19–49 years were classified into four groups according to the regularity of meal intake: threemeal regular diet (3MRD), two-meal regular diet, one-meal regular diet, and irregular diet (IRD). Food and nutrient intake was assessed using the 24-hour recall method and estimated by a generalized linear model in complex sample weight variables.

Results: In IRD, there were relatively more females who were not married, lived alone, or reported low levels of education. As subjects ate more meals, more people felt thinner and healthier by themselves. Dietary intake of cereal, vegetables, seaweed, and fiber was directly proportional to the number of regular meals as well as essential components such as water, carbohydrates, protein, fat, and micronutrients. Contrarily, alcohol and beverage consumption was inversely proportional to the number of regular meals. Intake level of legumes, fish, fruits, seasonings, milk, oils, sugars, and cholesterol was consistent regardless of meal frequency.

Conclusion: Our findings suggest that 3MRD showed nutrient adequacy and a healthier profile on body weight, body mass index, waist circumference, blood pressure, serum fasting glucose, total cholesterol, and triglyceride.