INS and diabetes mellitus: In 2014, an SRMA of 12 RCTs assessing the effect of tree nuts on glycemic control in people with diabetes (n = 240) showed a significant lowering in fasting glucose (8 comparisons, MD = −0.15 mmol/L; 95% CI: −0.27, −0.02 mmol/L; I2 = 35%) and HbA1c (8 comparisons, MD = −0.07%: 95% CI: −0.10, −0.03%; I2 = 37%), with no significant effect on fasting insulin or HOMA-IR [35].