Associations of eating context with dietary quality, satiety, and postprandial blood glucose in free-living Singaporean adults during 9 days of intensive digital phenotyping

Abstract Background Eating behaviors are shaped by contextual factors such as where people eat, who they eat with, and their activities and mood during meals. However, data on these determinants of food choice in Asian populations are limited. We examined how eating context is associated with dietary quality, satiety, and postprandial blood glucose levels in an urban Asian population. Methods We analyzed data from up to 1291 Singapore residents aged 21–69 years (20,629 meals) in the Continuous Observations of Behavioral Risk Factors in Asia (COBRA) study. Over nine consecutive days, participants completed smartphone-based ecological momentary assessments six times per day, reporting meal composition, location, companions, concurrent activities, and premeal hunger, tiredness, stress, and happiness. We calculated diet quality scores for each meal (range 0–10). Masked continuous glucose monitors recorded interstitial glucose every 15 min, from which the 2-hour postprandial glucose was derived using incremental area under the curve. We estimated associations using generalized estimating equations, adjusting for sociodemographic, lifestyle, clinical, and other contextual factors. Results Meals were consumed at home (60%), hawker centers (local open-air food courts) (14%), the workplace (11%), other restaurants (9%), fast-food restaurants (2%), or other locations. Compared with home meals, diet quality was significantly lower at all out-of-home locations, particularly at fast-food restaurants (β: -0.70; 95% CI: -0.82, -0.57) and hawker centers (β: -0.56; CI: -0.63, -0.48). Postprandial glucose was higher after meals at hawker centers (β: 30.11 mmol/L*minute; CI: 20.11, 40.11) and the workplace (β: 17.48; CI: 4.34, 30.62) than at home. Eating with friends was associated with lower postprandial glucose than eating alone. Higher premeal happiness was associated with modestly higher diet quality, whereas greater premeal hunger was associated with higher postprandial glucose. Conclusions In this urban Asian setting, eating location was a key determinant of meal quality and postprandial glycemic response. Hawker centers and fast-food restaurants were associated with worse diet quality, and hawker centers and workplace venues with higher postprandial glucose. Interventions that support home-prepared meals and promote healthier food options when eating away from home may improve cardiometabolic health.