The most commonly used method in the management of body compositions of healthy individuals in the recent times is the application of physical activity together with a healthy nutrition (diet). The application of diet together with physical activity cause significant changes in the body composition (fat ratio, muscle mass, lean body mass, etc.). Physical activity can be done with traditional physical activity methods as well as with virtual reality applications. Virtual reality is a simulation or a metaversal facet of a real environment created by a computer or various other electronic devices that allows one or more users to interact with certain elements in a simulated virtual frame through a human-machine interface. Virtual reality applications are generally classified as immersive and non-immersive virtual reality . Commercial games such as Sony Playstation, Microsoft Kinect Xbox 360, Nintendo Wii can be given as examples of non-immersive virtual reality . In order to preserve body composition, different exercise applications can be recommended in addition to the diet program. In the literature, many studies involving diet, physical activity or a combination of these two applications have been experimentally planned and carried out in a controlled manner. In these studies, moderate body weight loss (1-5 kg) was reported with only physical activity. It is a general opinion that diet therapy in addition to planned physical activity (exercise) provides more effective and healthier results than people who lose weight with only diet programs or only exercise. It has been stated in previous studies that body composition and physical fitness improve with virtual reality application as happened wih diet intervention. However, due to the fact that access to virtual reality applications is not very easy, longitudinal studies are needed to evaluate whether they should be included in general body composition and physical fitness improvement programs. At this point, the main purpose of this study is to compare and evaluate the effects of virtual reality applications and healthy nutrition program on improving body composition and physical fitness.

Physical inactivity is one of the main causes of many diseases. The development of technology causes some activities in daily life not to be performed and physical activity to decrease. Many diseases such as obesity, cardiovascular diseases and diabetes are more common in inactive and sedentary individuals.

In order to maintain body weight in sedentary individuals, the energy intake and expenditure must be equal. Today, mechanized social life reduces physical activity and keeps the energy that needs to be spent in the body, and this accumulation negatively affects the balance of energy intake and expenditure. In recent years, the increased consumption of highly processed food and beverages has caused changes in the world's diet. The main changes observed include imbalance in energy intake, change in eating frequency, and faster production and consumption of food. Obesity is not only among adults due to the decrease in physical activity in the world and in our country, the time spent in front of the television and computer reaching serious levels, high-energy - high-fat foods becoming more accessible and cheaper, and the rapid increase in industrial food production that is rich in salt but poor in fiber and vitamins; It is also seen among children and adolescents.

The most commonly used method today in the management of body composition of healthy individuals is the implementation of physical activity along with healthy nutrition (diet). Application of diet along with physical activity creates significant changes in body composition (fat ratio, muscle mass, lean body mass, etc.). Physical activity can be done with traditional physical activity methods or with virtual reality applications.

Virtual reality is a simulation or metaversal aspect of a real environment created by a computer or other various electronic devices that allows one or more users to interact with certain elements in a simulated virtual framework through a human-machine interface. Virtual reality applications are generally classified as immersive and non-immersive virtual reality . In immersive virtual reality, the user's interaction with the real world is usually limited by using virtual reality glasses. In non-immersive virtual reality, the user can manipulate the avatars on the screen, thanks to sensors that detect body movements, in order to maintain their connection with the outside world. Non-immersive virtual reality applications generally include a display, a receiving sensor, and a main application device. Commercial games such as Sony Playstation, Microsoft Kinect Xbox 360, Nintendo Wii can be given as examples of non-immersive virtual reality.

It has been observed that the use of virtual reality applications as a rehabilitation approach in various diseases has increased over the last 2 decades. It is seen to be used in areas such as stroke rehabilitation, various psychotherapy applications, improving physical fitness and improving body composition. Physical activity and nutrition are one of the few consistent factors associated with body composition. In addition to the diet program, different exercise practices can be recommended to maintain body weight. In the literature, many studies involving diet, physical activity, or combinations of these two practices have been experimentally planned and carried out in a controlled manner. In these studies, moderate body weight losses (1-5 kg) were reported only with physical activity . It is a general opinion that a healthy nutrition program, in addition to planned physical activity (exercise), provides more effective and healthy results than people who lose weight with diet programs or exercise alone. Just as body composition and physical fitness improve thanks to diet practices, it has been stated in previous studies that changes in body composition are also observed thanks to virtual reality-based physical activity applications. However, since access to virtual reality applications is not very easy, longitudinal studies are needed to evaluate whether they should be included in programs to improve general body composition and physical fitness.

The aim of this study is to compare and evaluate the effects of virtual reality-based physical activity applications and a healthy nutrition program on improving body composition and physical fitness.

The sample of the study will be female adult volunteers. The total number of participants required for the study to provide 92% accuracy was calculated as 27 people in the G power 3.1 program, based on the study of Zeng et al. (2021). A consent form will be obtained from each participant. Approval was received for this research from Erzurum Technical University Ethics Committee.

The sample of the study will consist of healthy individuals between the ages of 18-64 who do not have any health problems and do not need a special diet, living in Erzurum.

Exclusion criteria of the study: BMI value of 40.0 and above will prevent the implementation of a healthy nutrition program and virtual reality-based physical activity applications.

having situations. A total of 45 healthy individuals are planned to participate in the study. Participants will be classified into three groups using the stratified randomization method so that their current Body Mass Index (BMI) average and physical activity levels are equal. There will be 15 participants in each group.

Inclusion Criteria:

• Having BMI value between 25.0-39.9
• Female gender
• Volunteer between the ages of 18-64
• Not having any cardiovascular or orthopedic problems that would prevent attendance

Exclusion Criteria:

• Having a BMI value of 40.0 and above
• Having conditions that would prevent the implementation of a healthy nutrition program and virtual reality-based physical activity practices.

It will consist of healthy female individuals between the ages of 18-64.