Robust evidence for nutrition therapy for gestational diabetes (GDM) is lacking. Preliminary data suggested our CHOICE diet, higher in complex carbohydrate (60%) and lower in fat (25%) reduced fasting glucose (FBG), free fatty acids (FFA), and newborn adiposity (NB%fat). We tested the hypothesis that 7-8 wks of CHOICE would improve insulin resistance, reduce 24-hr glucose, FFA and NB%fat (2-wk PeaPod; 1° powered outcome) vs a conventional low-carbohydrate (40%), higher fat (45%) diet (LC/CONV). After diagnosis (~28-30 wks), 59 BMI-matched diet-controlled GDM women (mean±SD; BMI 32±5) were randomized to a eucaloric CHOICE or LC/CONV diet (7.2±1 wks; all meals provided). At baseline, a 2-hr 75g OGTT (with insulins) was performed and diet initiated. On day-4, a breakfast meal (30% of total calories) was given with fasting and hourly blood drawn x5 (glucose, insulin, FFA, triglycerides[TG]) for area-under-the curve (AUC). Measures were repeated at 36-37 wks. A CGM was worn for 72 hrs in wk 31 and 36. Of 59, 13 met exclusions (4 diet failures, 2/group). By ANCOVA (n=23/group), total and weight gain during diet were similar (CHOICE 1.9 vs LC/CONV 1.8 kg) as was delivery wk (39.2 vs 39.3 wks). At 37 wks, the meal glucose (p=0.001) and insulin AUCs (p=0.013) were lower for LC/CONV, though fasting glucose/insulin were similar. TG increased similarly. The FFA AUC decreased from 30-37 wks on CHOICE but rose on LC/CONV (p=0.016), and was lower for CHOICE at 37 wks (p=0.009). By the 37-wk OGTT, FBG decreased within both groups (CHOICE -7.2, LC/CONV -3.5 mg/dL, both p<0.01) but CHOICE led to improved (p=0.001) and lower glucose AUC (p<0.05)(similar insulin AUCs). Birthweight (3293 vs 3303 g), anthropometrics, NB%fat (10.8±4 vs 10.3±4%), and cord blood glucose, C-peptide, FFA and TG were similar. At wk 36, fasting (90±3 vs 86±3), 1-hr (117±4 vs 119±3), 2-hr PP (108±3 vs 106±3), 2-hr PP AUC, time in range (88±2 vs 88±1%), and 24-hr AUC remained highly similar between diets (p>0.05 all).This RCT shows that complex carbohydrate can be liberalized by 20% above conventional recommendations and may improve glucose tolerance and similarly normalize fetal growth, expanding nutrition options in GDM.