Methods	Individual Randomized Controlled Trial in family health center in Istanbul, Turkey
Participants	Inclusion criteria: Pregnant women aged over 18, who had no health problems, did not intend to lose weight in pre‐pregnancy period, got pregnant in natural ways for two times at most, and were pregnant for a period of 3 months or less, were included in the study. Exclusion criteria: Six people from intervention and control groups were excluded from the study due to reasons such as not coming to regular follow‐ups and pregnancy complications. Age [Mean (SD)]: ‐ Intervention, Control: 24.31 (4.22), 24.28 (4.15) Working status [n (%)]:‐ Intervention, Control: 7 (15.6), 2 (4.4) Education mean (years): ‐ Intervention, Control: 6.6 (2.8), 7.6 (3.2) Income [n (%)]:‐ Intervention, Control: Low: 15 (33.3), 11 (24.4) Middle: 30 (66.7), 34 (75.6) High: 0, 0
Interventions	Intervention—Lifestyle intervention (n = 51) Description: Four meetings were held with women regarding healthy lifestyle, nutrition, exercise, and weight follow‐up. At every meeting, objectives of nutrition and physical activity for optimal GWG were specified until the next meeting. Women reaching their objectives were praised and encouraged. Nutrition and physical activity levels of women who could not reach their objectives were reviewed with women, and a more intensive consultancy (repetition of basic nutrition and physical activity recommendations, reviewing individual objectives, and supportive phone consultancy) was provided. Interviews made in weeks 12–15, 16–18, and 20–24, a 15‐min health training prepared in the computer was carried out and then brochures were delivered. Each of these interviews lasted for about 1 h. In gestational weeks 12–15, the women were interviewed regarding the importance of healthy life and health practices. In gestational weeks 16–18, inter‐views were held concerning physical activity and exercises. Low‐level aerobic exercises recommended for pregnancy were shown and performed. Women were recommended to do mild‐moderate safe exercise types, which increase the heart rate to maximum 140 beats/min while being easily able to talk, for 30 min every other day (elliptical trainer, swimming, pilates, yoga, golf adapted for pregnancy, and mild level aerobic exercises), and maintain a more active lifestyle (taking walks every day, going to work by walking, using stairs instead of elevators, participating in sportive activities in their leisure times). In gestational weeks 20–24, interviews regarding nutrition were held. Women were informed about the basic nutrition principles (eating small but frequent meals at least 5 times a day, having breakfast every day, portions and amounts required to be consumed from all food groups, lessening consumption of sweet foods to once a day or less, increasing fibrin intake from bread, and decreasing fat in diet). Recommendations for consuming more healthy foods (e.g., fruit) instead of foods containing intensive energy (e.g., fast food and sweets) without any energy limitation according to the personal dietary habits were given. In week 37, only weights were followed up. Nutrition counseling messaging: Pender‚ health promotion model was used to allow women to express their experiences and opinions through open‐ended questions, e.g., what problems (barriers) you may have to eat healthier foods (more vegetables, more fruits, lower‐fat foods, and healthy grains), regarding nutrition and physical activity. Therefore, counseling, and behavioral skill‐building interventions were personalized according to the barriers for the individuals to displaying the behavior and their self‐efficacies in terms of performing the behavior. Women were informed about the importance of gaining weight within the recommended range and maintaining a healthy life. Intervention adapted to local context: Not reported Women empowerment approach: Partial empowerment model Control (n = 51) Description: Women are generally followed up by at least four times by midwives or nurses in standard care. In every follow‐up, weights of women are measured; however, they are not informed on what the GWG range appropriate for their BMI is and their personal weight changes.
Outcomes	Gestational weight gain, mode of delivery, Dietary intake during pregnancy, Macronutrient intake during pregnancy,
Notes	Funding: This study did not receive grant from any institution or organization.