Purpose: Considering that students are highly influenced by education, the purpose of this research is to what extent combined exercises and nutritional education have an effect on improving the body composition and physical fitness of overweight and obese students.
Methodology: The present research method is semi-experimental. The statistical population was the students of Toseeh school in Tehran. 38 obese and overweight students in the age range of 10-12 years who were eligible to participate in the research were selected and randomly divided into three groups. 1- Combined exercises + nutritional training 2- Combined exercises 3- Control (without training and nutritional training). Combined exercises including aerobic exercises, resistance exercises with body weight bearing and handball games were performed in the four bells of their sport, which were on four days of the week. Each exercise call was 50 minutes. Exercises were performed with an intensity of 50 to 90% of the maximum heart rate. The nutrition education program of the group receiving nutrition education was in person for two sessions, each session lasting 30 minutes for two weeks. The content was about food ingredients, overweight and obesity, causes of overweight and obesity, ways to prevent and treat overweight and obesity. They were also given pamphlets about this. Body composition variables including height, weight, waist circumference and BMI were measured with a tape measure, scale and calculator, and some physical fitness factors including agility, upper and lower body strength, shoulder girdle muscle endurance, sprinting, aerobic capacity and flexibility with tests T-agility, chest press and deadlift, modified Swedish swimming, 30m sprint, 540m sprint and sitting and forward bending test were measured. Tests were taken before and after eight weeks of study. Descriptive and inferential tests were used to evaluate the data. In fact, after determining the normality of the data by the Shapiro-Wilk test, the covariance and Bonferroni tests were used to compare the groups. A significance level of P<0.05 was considered.
Results: The results showed that agility, speed, flexibility, muscular endurance, upper body strength and body weight improved significantly in the group of combined training with nutritional training compared to the control group. Agility and speed variables improved in the combined training group compared to the control group. At the end of the study, the combined exercise group with nutritional training gained significantly better agility and upper body strength than the combined exercise group.

Conclusion: nutrition training along with combined exercises is a suitable method to control body weight and improve physical fitness performance.