Table 2

Results of the analyses of comparing a diet high in plant-derived PUFA with SFA or carbohydrates, on absolute changes in fasting glucose, insulin and HOMA-IR, based on fixed effects models

Study characteristicStratification variableGlucoseChange versus control, mmol/L (95% CI)P value*InsulinChange versus control, pmol/L (95% CI)P value*HOMA-IRChange versus control, units (95% CI)P value*
Comparisons (n)Comparisons (n)Comparisons (n)
Overall15−0.01 (−0.06 to 0.03)0.58517−2.6 (−4.9 to −0.2)0.03011−0.12 (−0.23 to −0.01)0.031
Replacement nutrientSFA13−0.03 (−0.07 to 0.02)0.14114−2.4 (−4.9 to 0.1)0.7639−0.13 (−0.24 to −0.01)0.584
Carbohydrates20.07 (−0.05 to 0.18)3−3.5 (−9.7 to 2.8)20.01 (−0.47 to 0.49)
Dose–response, continuousPer 5%En15−0.07 (−0.17 to 0.04)0.23317−5.8 (−10.2 to −1.3)0.01111−0.24 (−0.56 to 0.07)0.132
PUFA doseTertile 1†5−0.01 (−0.08 to 0.06)0.20351.5 (−4.6 to 7.6)0.0202−0.13 (−0.54 to 0.28)0.031
Tertile 250.02 (−0.05 to 0.09)6−0.5 (−3.9 to 2.8)50.02 (−0.13 to 0.17)
Tertile 35−0.09 (−0.18 to 0.01)6−6.7 (−10.5 to −2.9)4−0.28 (−0.45 to −0.12)
PUFA typeOmega-6 PUFA14−0.01 (−0.06 to 0.04)1711
Omega-3 PUFA100
Intervention duration≤4 weeks80.00 (−0.06 to 0.05)0.5938−4.6 (−8.7 to −0.6)0.2145−0.05 (−0.37 to 0.26)0.657
>4 weeks7−0.03 (−0.10 to 0.04)9−1.5 (−4.4 to 1.3)6−0.13 (−0.25 to −0.01)
DesignCrossover11−0.03 (−0.08 to 0.02)0.21111−5.0 (−8.3 to −1.7)0.0388−0.23 (−0.39 to −0.07)0.078
Parallel40.04 (−0.05 to 0.14)6−0.1 (−3.4 to 3.2)3−0.03 (−0.18 to 0.11)
Industry fundingNo7−0.04 (−0.13 to 0.05)0.4899−3.5 (−6.8 to −0.1)0.2005−0.19 (−0.33 to −0.05)0.115
Partial/full80.00 (−0.05 to 0.05)6−0.1 (−4.0 to 3.7)6−0.02 (−0.18 to 0.15)
Control over food intakePartial40.01 (−0.08 to 0.11)0.5266−3.0 (−6.0 to 0.0)0.6673−0.03 (−0.18 to 0.11)0.078
Full11−0.02 (−0.07 to 0.03)11−1.9 (−5.8 to 2.0)8−0.23 (−0.39 to −0.07)
Study outcomePrimary13−1.1 (−7.2 to 5.0)0.6090
Not primary14−0.01 (−0.05 to 0.03)14−2.8 (−5.4 to −0.3)11
Risk of bias0 unclear risk5−0.05 (−0.13 to 0.02)0.1995−1.7 (−4.9 to 1.5)0.6985−0.11 (−0.23 to 0.01)0.658
1 unclear risk80.00 (−0.06 to 0.05)6−4.1 (−9.7 to 1.5)5−0.06 (−0.37; to 0.26)
≥2 unclear risk20.12 (−0.06 to 0.31)6−3.3 (−7.5 to 1.0)1
SFA sourceDairy9−0.02 (−0.08 to 0.04)0.9549−3.7 (−6.9 to −0.4)0.3146−0.14 (−0.28 to 0.00)0.909
Plant3−0.04 (−0.12 to 0.05)2−2.2 (−8.0to 3.5)2−0.09 (−0.31 to 0.12)
Unspecified132.4 (−4.7 to 9.4)1
  • *For subgroups, p value <0.05 indicates a significant difference in pooled effect sizes between subgroups; for continuous data, p value <0.05 indicates asignificant linear effect.

  • †Tertiles of PUFA difference per outcome: glucose, t1: ≤6.3; t2: 6.3≤8.4; t3: >8.4; insulin, t1: ≤6.3; t2: 6.3≤9.0; t3: >9.0; HOMA-IR, t1: ≤4.5; t2: 4.5≤8.4; t3: >8.4 En%.

  • En%, percentage of daily energy; HOMA-IR, homeostatic model assessment-insulin resistance; n, number; PUFA, poly-unsaturated fatty acids; SFA, saturated fatty acids.