Characterisation of breakfast, lunch, dinner and snacks in the Japanese context: an exploratory cross-sectional analysis

Objective: To characterize different meal types, by examining the contribution of specific meals to the total intakes and the nutritional quality of each meal. Design: A cross-sectional analysis was conducted based on dietary data collected using 4-day dietary record. Diet quality was assessed by the Healthy Eating Index-2015 and Nutrient Rich-Food Index 9.3. Setting: Japan. Subjects: Adults aged 20-81 years (n 639). Results: Diet quality was, on average, highest for dinner, followed, in order, by lunch, breakfast, and snacks. Breakfast, lunch, dinner, and snacks, on average, accounted for 21%, 32%, 40%, and 11% of total energy intake, respectively. For many nutrients, the percentage contribution to total intake did not vary within each meal, broadly in line with that for energy: 18%-24% for breakfast, 26%-35% for lunch, 35%-49% for dinner, and 4%-15% for snacks. However, intakes of many foods largely depended on one meal type. The foods mainly eaten at dinner were potatoes, pulses, total vegetables, fish, meat, and alcoholic beverages (52%-70%), in contrast to noodle (58%) at lunch and bread (71%) and dairy products (50%) at breakfast. The foods mainly eaten at snacks were confectioneries (79%) and sugar sweetened beverages (52%). Conversely, rice and eggs were more evenly distributed across three main meals (19%-41% and 30%-38%, respectively), while fruit and noncaloric beverages were more evenly distributed across all meal types (17%-30% and 19%-35%, respectively). Conclusion: These findings provide the background information on each meal type in Japanese and may help inform the development of meal-based guidelines and public health messages.