Participants were pregnant women at increased risk for
GDM. Women were considered to be at increased risk forGDM
if they were obese (body mass index [BMI] 30) or overweight
(BMI 25) and had at least 1 of the 3 following characteristics:
1) history of macrosomia (offspring with a birth weight above the
97th percentile of gestational age); 2) history of GDM; 3) firstdegree
relative with diabetes type 2. Exclusion criteria included
recruitment after 20 weeks of gestation age, under 18 years of
age, inadequate knowledge of the Dutch language, diagnosis of
(gestational) diabetes mellitus before randomization; hypertension;
alcohol abuse; drug abuse; use of medication that affects
insulin secretion or insulin sensitivity; serious pulmonary, cardiac,
hepatic, or renal impairment; malignant disease; serious
mental or physical impairment (ie, preventing understanding or
implementing the study protocol).