Nutrient intake order on metabolic outcomes in type 2 diabetes: a systematic review and meta-analysis
摘要
Macronutrient sequence has been proposed as a practical strategy to improve postprandial glycemia in individuals with type 2 diabetes (T2D). However, current evidence remains inconclusive. This meta-analysis aims to provide an updated evaluation of the impact of a carbohydrate-last (CL) strategy, compared to carbohydrate-first or unordered (CF) intake, on metabolic parameters in adults with T2D.
MethodsA systematic search was conducted in PubMed, Embase, and Cochrane Central for randomized controlled trials (RCTs) evaluating nutrient intake order in T2D. Outcomes were analyzed using mean difference (MD) with 95% confidence intervals (CI) under a random-effects model. Heterogeneity was assessed using Cochrane’s Q test and I² statistics. Analyses were conducted using R, version 4.4.2.
ResultsSeventeen studies involving 389 participants were included, with 114 (29%) in a parallel design and 192 (49%) in a crossover design receiving CL. In the pooled analysis, the CL group had significantly lower postprandial glucose at 60 min (MD: -42.73 mg/dL; 95% CI: -55.51, -29.96; p < 0.01) and 120 min (MD: -13.00 mg/dL; 95% CI: -21.07, -4.94; p < 0.01), higher postprandial glucagon-like peptide-1 (GLP-1) levels (MD: 8.21 pmol/L; 95% CI: 2.34, 14.09; p < 0.01), delayed gastric emptying half-time (MD: 28.14 min; 95% CI: 16.06, 40.23; p < 0.01), and reduced glycated hemoglobin (HbA1c) at follow-up (MD: -0.16%; 95% CI: -0.31, -0.01; p = 0.04).
ConclusionCarbohydrate-last eating pattern has been shown to improve postprandial glycemia, enhance GLP-1 secretion, and delay gastric emptying, with a minimal effect on HbA1c in individuals with mild T2D. Further research is needed to confirm its applicability in advanced disease stages and to establish long-term metabolic benefits.