No dietary strategies have been designed and proved for Mexican pregnant women with diabetes. This is a randomized clinical trial of pregnant women with pregestational type 2 diabetes and gestational diabetes that were followed every two weeks until labor to assess the impact of the MNT program on metabolic control, maternal and fetal nutritional status and cost effectiveness. Participants were randomly assigned to one of three medical nutrition therapy (MNT) groups: the MNT 1 group (n=38) received usual medical treatment, counseling from a nutritionist and diabetes educator, using carbohydrate counting (40-45% of carbohydrates)with an intensive educational component; MNT2 group (n=50) had the same treatment, but included only low-moderate glycemic index foods; and NO-MNT group (n=45) received the current hospital treatment. All women will receive a glucose meter so they do self glucose monitoring (pre and postprandial) 2 times a weeks 6 times a day. Weight gain, dietary consumption and glucose concentrations will be evaluated every two weeks. Fetal outcomes (weight, length and presence of complications)will be measured at labor.

Inclusion Criteria:

• pregnant women with gestational diabetes (Freinkle´s classification: type A2 and B1) or pregestational type 2 diabetes.
• less than 30 weeks of gestation
• women who plan to attend their pregnancy at the institution (INPerIER)

Exclusion Criteria:

• women with type 1 pregestational diabetes or gestational diabetes type A1.
• women with multiple pregnancies
• women with renal or hepatic disease
• women who could not follow the dietary recommendations within the study