Meal pattern matters: Associations of meal-specific dietary patterns with postprandial glucose response in free-living adults with obesity

Background & aims: Impaired postprandial glucose is associated with increased risk of type 2 diabetes and all-cause mortality. Although dietary intake influences glucose response, meal-specific postprandial glucose responses under free-living conditions remain poorly characterized in adults with obesity. This cross-sectional study examined whether dietary intake at breakfast and lunch relates to subsequent postprandial glucose, and whether dinner intake relates to both postprandial and nocturnal glucose. Methods: Participants wore a continuous glucose monitoring (CGM) device for 14 days, and dietary intake was assessed using one or two non-consecutive 24-h recalls. Energy, macronutrients, food groups, and dietary patterns were derived. CGM data were time-matched to breakfast, lunch, and dinner to derive postprandial parameters (0–180 min), and nocturnal metrics were derived during the sleep period time. Results: A total of 146 participants (73 women; median [Q1–Q3] age: 49.5 [42.0–55.0] years) with valid data were included in this analysis. Higher intakes of fruit, dairy, and unsweetened beverages (all β≤ −1.1 × 10−4 per 5%EI increase), and lower consumption of high-carbohydrate dietary patterns at lunch (all non-linear P≤ 0.005) were associated with lower postprandial glucose variability. At dinner, greater intake of alcoholic drinks, processed meats, and refined bread or pasta was associated with detrimental nocturnal glucose responses (all β≥ 3.9 × 10−5 per 5%EI increase), whereas higher fruit intake showed the opposite pattern (all β ≤–2.1 × 10−5 per 5%EI increase). Conclusion: These findings highlight the dynamic relationships between meal-specific dietary intake and subsequent glucose responses in free-living adults with obesity, with potential implications for precision nutrition strategies to improve glucose regulation.