The aim of this pilot study is to conduct a dietary intervention for overweight (body maas index BMI≥25) and obese (BMI≥30) pregnant women in two maternity care clinics and explore the effect of the intervention on gestational weight gain and the prevalence of gestational diabetes between the intervention and control groups.

Half of the women are allocated to the intervention group and another half for the control group. The intervention group will get written material of healthy diet during pregnancy as well as emphasized nutritional guidance given by public health nurses at each visit in the maternity care clinic. There will also be two group meetings with a dietitian. The control group will get the same written material, but otherwise basic care and guidance at each visit in the maternity care clinics. The collected data of both groups include the information on weight gain, the result of an oral glucose tolerance test and 4 day food records, Three factor eating questionnaire (TFEQ R-18) and Binge Eating Scale (BES).

Inclusion Criteria:

• Age less than 35 years
• BMI 25 or over
• healthy, no chronic medical conditions
• singleton pregnancy
• first trimester of pregnancy at the time of recruitment

Exclusion Criteria:

• Age 35 and older
• BMI less than 25
• chronic medical conditions
• multiple pregnancy
• pregnancy at second or third trimester at the time of recruitment

Eligibility is based on gender