Lifestyle determinants of glycemic responses to snacking in free-living adults without diabetes: an intensive longitudinal observational study.

BACKGROUND

Snacking is common and can contribute to blood glucose fluctuations. However, large studies investigating lifestyle determinants of glucose responses to snacking under real-world conditions are scarce.

METHODS

In this intensive longitudinal observational study, we analyzed data from 3,325 snacking episodes captured by ecological momentary assessment surveys (six daily), continuous glucose monitoring, and accelerometry over nine free-living days among 785 male and female adults aged 21-69 years without diabetes in Singapore. Postprandial glucose responses were assessed using 2-hour postprandial glucose incremental area under the curve (iAUC) following snacking episodes. Lifestyle exposures included consumption of snack foods and beverages, snack timing, postprandial physical activity, and daily physical activity and sleep prior to snacking episodes. Linear mixed-effects models were used to estimate within-person and between-person associations between these exposures and 2-hour postprandial glucose iAUC.

RESULTS

The average 2-hour postprandial glucose iAUC was 63.8 (SD: 61.8) mmol/l*minute after snacking episodes. Consumption of bread or buns (within-person β: 30.7; 95% CI: 20.4, 41.1), deep-fried foods (β: 19.8; CI: 9.2, 30.4), sweets (β: 14.6; CI: 6.6, 22.6), and sugary beverages (β: 12.2; CI: 4.3, 20.0) was associated with higher glucose iAUC. In contrast, greater postprandial moderate-to-vigorous physical activity was associated with a lower glucose iAUC (β: -28.4 per hour; CI: -49.2, -7.5). In addition, glucose iAUC was higher following afternoon snacking (β: 9.3; CI: 2.0, 16.6) and early evening (β: 10.7; CI: 2.5, 18.9) than morning snacking.

CONCLUSIONS

Snack composition, snack timing, and postprandial physical activity were associated with postprandial glucose responses to snacking in adults without diabetes. Recommendations on snacking-related lifestyle behaviors may improve glycemic control in daily life.