Consumption of a diet containing soy protein (35% animal protein, 35% soy protein, and 30% other plant proteins) for 6 weeks by women aged 18–40 years (at week 24–28 of gestation) with gestational diabetes mellitus (n = 34) was associated with significant improvements in fasting plasma glucose, serum insulin levels, homeostasis model of assessment—insulin resistance, and quantitative insulin sensitivity check index compared with the control diet group consisting of 70% animal and 30% plant proteins (n = 34) [99]. This evidence concerns the gene INS and gestational diabetes.