In this study, two groups, randomized clinical trial that aim of determining the effect of healthy nutrition training and physical activity with Pedometer on weight changes and weight-efficacy of life style woman with high body mass index in postpartum period. Sample size includes 64 obese and overweight women who go to the health center at 6-16 weeks postpartum. For sampling, Mashhad Center No. 2 and No. 3 were selected. The among their subsidiary centers, randomly, four centers are selected as interventions and four centers are selected as controls. The training is carried out by a researcher in groups of 5 to 7. Teaching is a lecture method, a question and answer that takes place in two sessions (90-60) minutes a week, once a week. Session One: Measurement of anthropometric index and body composition, completion of questionnaires including Clark's Weight Lifestyle Self-Efficacy Questionnaire, Physical Activity Indicator Questionnaire, an explanation on how to fill out a checklist of food and daily physical activity, then training Regarding physical activity and its benefits during postpartum period, and the method of using the pedometer is given. Second session: Training on healthy nutrition counseling and people will be taught to choose their food according to the food substitution list At the end of the session, a healthy lifestyle education booklet (with content of physical activity and healthy nutrition advice) will be presented. In the intervention group, after the completion of the training in the 2nd and 6th weeks, a telephone call is made to follow up the research units. The control group will receive routine care. Maternal weight at the end of weeks 4 and 8 is monitored in both groups, then the mean weight changes and lifestyle self-efficacy related to weight at the end of week 8 will be compared between the two groups.