Achieving glycemic control is essential in the prevention and management of metabolic disorders, with several dietary strategies having been proposed. Meal sequence, which is defined as the order of food consumption while maintaining the overall composition and intake, may attenuate postprandial glycemic responses. This systematic review aimed to assess the effects of meal sequences on postprandial glycemic responses in healthy adults and explore its potential as a preventive strategy for glycemic control.
Methods Literature published between January 2015 and March 2025 in PubMed, Cochrane Library, Web of Science, KoreaMed, and RISS was searched using the keywords “healthy adult,” “food order,” “meal sequence,” and “glucose response.”
Results Among the 2,442 records identified, one randomized controlled trial, four randomized crossover studies, and one repeated-measures design with a total of 107 participants aged 20–36.7 years met the inclusion criteria. Most of the studies reported that consuming vegetables, fruits, or protein-rich foods before carbohydrate-rich foods reduced postprandial glucose responses and incremental area under the curve compared with mixed or carbohydrate-first meals. These effects were also noted in randomized controlled trials and randomized crossover design.
Conclusion Our findings indicate that adjusting the order of food consumption can effectively mitigate acute postprandial glucose responses in healthy individuals. Further large-scale and long-term randomized controlled trials across diverse populations and standardized protocols are warranted to strengthen the evidence base.
Numerous clinical trials have examined the beneficial effects of Juglans regia leaf extract (JRLE) in patients with type 2 diabetes mellitus (T2DM); however, the results of these studies are inconsistent. Therefore, we conducted the current systematic review and meta-analysis to evaluate the effect of JRLE on glycemic control and lipid profile in T2DM patients. We searched online databases including PubMed, Scopus, EMBASE, and Web of Science for randomized controlled clinical trials that examined the effect of JRLE on glycemic and lipid indices in T2DM patients. Data were pooled using both fixed and random-effect models and weighted mean difference (WMD) was considered as the overall effect size. Of the total records, 4 eligible studies, with a total sample size of 195 subjects, were included. The meta-analysis revealed that JRLE supplementation significantly reduces fasting blood glucose (WMD, −18.04; 95% confidence interval [CI], −32.88 mg/dL, −3.21 mg/dL; p = 0.017) and significantly increases fasting insulin level (WMD, 1.93; 95% CI, 0.40 U/L, 3.45 U/L; p = 0.014). Although the overall effect of JRLE supplementation on hemoglobin A1c was not significant, a significant reduction was seen in studies with an intervention duration of > 8 weeks (WMD, −0.64; 95% CI, −1.16%, −0.11%; p = 0.018). Moreover, we also found no significant change in lipid parameters. Our findings revealed a beneficial effect of JRLE supplementation on glycemic indices in T2DM patients, but no significant improvement was found for lipid profile parameters.
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