The purpose of the study is to test whether four lifestyle intervention programs (diet alone; diet and behavioral therapy, diet and exercise, diet and behavioral therapy and exercise), delivered to women with GDM during 24-26 weeks of gestational age will help women to improve their metabolic pattern, and decrease the incidence of adverse maternal and neonatal outcomes.

Women with gestational diabetes (GDM) are at increased risk of adverse pregnancy and neonatal outcomes. It is estimated that most women diagnosed with GDM can achieve targeted glycemic goals with nutrition therapy alone. A moderate exercise is recommended to lower serum glucose and to improve insulin sensitivity. Despite this, few reports examine the effect of exercise on glucose intolerance during pregnancy. Furthermore, no trial on the efficacy of behavioral treatment in women with GDM is available.

The purpose of the study is to test whether four lifestyle intervention programs (diet alone; diet and behavioral therapy, diet and exercise, diet and behavioral therapy and exercise), delivered to women with GDM during 24-26 weeks of gestational age will help women to improve their metabolic pattern, and decrease the incidence of adverse maternal and neonatal outcomes.

Inclusion Criteria:

• Gestational age between 24 and 26 weeks
• Diagnosis of GDM at the 75g oral glucose tolerance test (OGTT)
• Singleton pregnancy

Exclusion Criteria:

• Body mass index > 40 or < 12kg/m2
• Any known diseases (pre-existing diabetes mellitus, cardiovascular diseases, liver/kidney diseases, cancers, arterial hypertension)
• Patients on any drugs