Bonomo 2005.

Methods	Randomised controlled trial.
Participants	300 Caucasian women with singleton pregnancies, with a positive 50 gram 1‐hour GCT test (≥ 7.8 mmol/l) followed by a normal 100‐gram OGTT according to Carpenter and Coustan's criteria (see notes). Women with one abnormal value at the 100‐gram OGTT or fulfilling Carpenter and Coustan's diagnostic criteria for GDM were excluded. Setting: The Diabetic and Pregnancy Centre of Niguarda Ca’Granda‘ Hospital in Milan, Italy.
Interventions	Women in the intervention group (n = 150) Dietary advice providing 24‐30 kcal /kg per day, based on prepregnancy body weight; caloric intake was divided into three meals and 2 or 3 snacks, and distributed as 50‐55% carbohydrate, 25‐30% protein, 20‐25% fat. Out‐patient management protocol: visits every 2 weeks, when the main clinical parameters (weight, blood pressure) were recorded, discussion of dietary habits with evaluation of therapeutic compliance, and measurement of fasting and 2‐h postprandial blood glucose, of HbA1c and fructosamine. Urine test every morning at home for ketone bodies. Women in the control group (n = 150) Women were reassured after testing. No special care, diet, or pharmacological treatment.
Outcomes	Maternal: caesarean section; infant: gestational age at delivery, birthweight, macrosomia (birthweight ≥ 4000 g), LGA (birthweight ≥ 90th centile), SGA (birthweight ≤ 10th centile), ponderal index, hypoglycaemia (any of 2 consecutive blood glucose values < 1.7 mmol/l), hyperbilirubinaemia (plasma values ≥ 205 µmol/l), polycythaemia (haematocrit > 60%), 5‐min Apgar score < 7, admission to neonatal intensive care unit.
Notes	Carpenter and Coustan’s diagnostic criteria Fasting: 5.3 mmol/L. 1‐hour: 10.0 mmol/l. 2‐hour: 8.6 mmol/l.  3‐hour: 7.8 mmol/l. 2 or more results equal to or greater than the cut‐off values is required for a diagnosis of GDM. Blood glucose targets were < 5 mmol/l fasting, and < 6.7 mmol/l 2‐h postprandial for women in the intervention group.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomly assigned to 1 of the 2 study groups, no other information available.
Allocation concealment (selection bias)	Unclear risk	No information was given on allocation concealment.
Blinding of participants and personnel (performance bias) All outcomes	High risk	All women, and the attending physicians were informed of the results of the GCT and OGTT. It is unclear whether research personnel are blinded from knowledge of group allocation; participants were unlikely to be blinded.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information on whether the outcome assessors were blinded or not.
Incomplete outcome data (attrition bias) All outcomes	High risk	Losses to follow‐up (2%): 6 women in the intervention group loss to follow‐up. Post‐randomisation exclusion (5%): 9 women in intervention group and 6 in the control group were excluded due to the diagnosis of GDM at 30‐34 weeks' gestation. All those women were described as "replaced".
Selective reporting (reporting bias)	Low risk	No obvious risk of selective reporting.
Other bias	Low risk	No obvious risk of other bias.