TABLE 4. Tecnological Solutions to Support the Family-Based Intervention Hierachy Model.

Childhood Obesity Family-Based Intervention Needs	OB CITY’s Solution
1.1 Parents have healthy diet habits It is proven that parents’ eating habits will directly affect their children [56], [57]. If parents have a long-term heavy intake of high-carbohydrate and high-fat foods, children will be exposed to excessive intake of calories [58]. Personal dietary preferences, irregular schedule and lack of expertise make parents just buy and prepare what is their favorite, what is fast and easy to do and what they think is good for health without considering the practical nutritional value of food. To change their eating habits, they need to recognize the problems of their diet habit which may cause a series of serious health problems and have the motivation to correct them; then, they should study nutritional facts to know what a good diet is; finally, they try to change their diet, and stick with it.	Provide nutrition, exercise, and emotional management system for parents OB CITY provides services to permit parents manage their eating behavior, exercise behavior and emotional balance. It will let parents to improve their behaviors through education, guidance, and supervision. At the education part, OB CITY will periodically send professional information related to nutrition, exercise and psychology to parents, so that they can slowly learn relevant knowledge to know how to establish a healthy lifestyle independently. At the guidance part, OB CITY will offer directly to parent lifestyle programs personalized according to their preference to facilitate their work of behavior control. Based on the parents’ choice of their life custom, the system will generate automatically a diet and activity plan, to let parent make the lifestyle healthier. At the same time, OB CITY uses affective computing techniques to detect the parents’ emotion with sensors (heart rate and electrodermal activity), informs them the state of their emotion and gives suggestions, to let them understand better their mood and try to control it. At the supervision part, the system provides two mechanisms: self-supervision and supervision by others. First, the system uses the gamification techniques, to motivate parents to follow well the lifestyle program proposed by the system, to modify their emotion and lifestyle. It also takes advantage of the social network, let parents to supervise and compete with each other and the link between parents end and the children end permits children to supervise their parents.
1.2 Parents are exercising Children can spend a lot of leisure time at home to do more physical exercise than at school. The parents’ exercise habits will influence their children [59]. The lack of physical activity is a frequent problem of our days, the economic growth, technological progress, and social changes have led many people to take public transport instead of walking, have sedentary jobs to carry out the work, watch TV, play video games and use the computer at home. To change this, parents must understand the benefit of physical exercise in a daily basis; also, they need to have access to relevant (and trustable) knowledge sources, so that they can efficiently carry out physical exercise according to their personal state.
1.3 Parents with balanced emotion Parents’ emotion in family life affects directly the children’s mental health. Parents often have bad mood at home, they fight and quarrel, even vent their negative emotion directly to the children, let children often live in tension and fear [53]–[55]. Children’s psychological problems will affect their behavior, lose self-confidence and self-control, become easy to give up and do not take the initiative to improve themselves. Parents in daily family life must control their emotions: do not quarrel or fight in front of children, do not complain about life or show decadent emotion in front of children, do not scold or criticize others in front of children, do not express their views in an extreme way in front of the children, and most important, do not scold the children directly.
1.4 Parents and children having good communication The relationship between parents and children might influence the children’s whole life, and also affect the inheritance of parents’ good behavior. In order to establish good relation between parents and children, parents need to offer children real accompany. Parents should try to find enough time to be close to the children, to play with them, chat with them and do other things with them as much as possible; and take the initiative to express their love for children at the same time. Besides that, parents should pay more attention to their children, share the anguish and joy of their children’s every problem and achievement. In the exchange and communication between parent and children, parents should offer enough freedom, respect, trust and patience, so that children can grow up in a comfortable home environment.	Create interaction between parents and children OB CITY includes the parents end and the children end and permits the mutual communication between the two ends. In this way, the system creates many opportunities for parents and children to realize online and offline interaction. Online interaction: several operations in the OB CITY’s user ends require direct or indirect interaction between children and parents. OB CITY sets up mechanisms for mutual supervision of children and parents, the behavior and emotion management module of parents end needs the children confirm the lifestyle and emotional state of their parents in children ends; at the same time parents plan and intervene the behavior modification of their children through the parent’s ends. OB CITY also sets different virtual roles for parents and children in the serious game, so that they might engage in a dialogue through their user ends to reach a mutual cooperation and encouragement in the game. Offline interaction: both parents and children ends will require from parents and children to complete some offline collaborative tasks, so that parents and children can exercise, change diet and learn together in real life, thus creating opportunities for them to communicate and understand each other.
2.1 Parents know basics of “behavior modification” Behavior modification is not a standard, step by step process, especially the behavioral intervention for childhood obesity [43]. Parents need to be able to deal with a wide variety of information, analyze it and provide feedback. Parents acquire a lot of information, not only about the children’s body, mind and behavioral state, but also other environmental information. Some of this information is very important for behavior modification, but some is interference information or noise. Parents should learn to accurately filter information in order to make the correct judgments and learn to customize the scientific program according to the children’s state. At the same time, parents should choose the right incentive methods to motivate children. They also should know appropriately adjust their intervention programs to respond to all kinds of unexpected random events during the long time intervention process.	Provide an intelligent Applied Behavior Analysis system OB CITY provides professional support in every behavior modification step in strict compliance with the ABA operation. In the OB CITY, parents need to enter personal information and basic behavior of their children, the system analyzes and provides some options of target behavior to let parents choose, and then generates different behavior modification programs according to parental choice. Finally, parents decide a program and the system converts it into every day’s tasks and delivers them to the children end. It also offers punishment or reward to encourage children to do these tasks in real life. In the intervention process, the system measures automatically children’s data by sensors (exercise and emotion data), and requires parents to record other children’s information (exercise and nutrition behavior), in such a way to provide more comprehensive observation of children without costing many parents’ time and energy. OB CITY also has an intelligent feedback system that not only shows to parents what the children have done, but also adjusts the behavior modification program automatically by learning the children’s state and behavior, and provides parents with better programs. If parents are willing to become more involved in the whole process and to be more resonsible of their children’s behavior modification, they can freely give veto the system’s recommendation and make their own decisions.
2.2 Parents know children’s clinical state Some children’s health data, including the child’s height, weight, Body Mass Index (BMI), Waist-hip Ratio (WHR) and body fat are related to the childhood obesity intervention. Parents need periodically to measure and record the physical data during the process, to get a better understanding of the treatment progress. Meanwhile, the children’s physical condition is also very important for the intervention: parents should avoid children’s innutrition and anemia for the diet; and also avoid the fatigue and injury by overdoing exercise.	Provide a comprehensive children monitoring system In the whole behavior intervention process, the parents are required to record a large number of children’s related data: physiological data, daily behavior, the emotional state, and some related environmental inputs. OB CITY creates regularly notifications to parents to alert them to record manually the children’s behavior and emotion every day, and to check the child’s physiological state each time. Meanwhile, OB CITY uses a variety of methods to acquire relevant children’s data directly: it is combined with various types of sensors (smart watches, smart bracelet) to detect the children’s motor behavior; it uses the Near Field Communication (NFC) technique to create children’s offline activity games and takes their motion data at the same time; it takes advantage of the social network, let the social members detect children’s eating behavior through an online game. In addition, OB CITY incorporates affective computing technique, through a combination of physiological data acquired by sensors, children’s performance in the life simulation game and the collected information from their online dialogue, helps in analysing the children’s emotion state.
2.3 Parents know children’s behavior Parents record and observe the children’s behavior throughout the entire process of behavior modification; they collect the children’s behavior in all the processes of Applied Behavior Analysis: the preparation, design, intervention and evaluation. The observation of behavior should be long-term and detailed. The children’s behavior can occur anywhere at any time. The parents should record it timely and accurately.
2.4 Parents know children’s character and mental state Without professional help, to understand children’s personality and psychology is very difficult for parents, even they live together, parents cannot totally know their children’s preferences and thoughts. Children’s feelings and personality have a high impact on the behavior modification. Cheerful children participate actively in the intervention and have a higher degree of adaptability; and sensitive children are susceptible to get various influences, thus affecting the modification progress [52]. Therefore, parents should know the children’s psychological status, in order to determine the most suitable plan.
3.1 Children engage with the intervention actively The children have to try again and again to complete similar tasks in the behavior modification, they need to do something they do not like or they are not used in performing under strict requirements. Sometimes, children do not know the importance of the intervention, they cannot give up their favorite food and they do not want to exercise, so they will never begin to change their accustomed behavior. And if they cannot find the pleasure during the process, and just suffer to do what they do not want to do, they will drop out quickly. Hence, children should have the motivation to participate, they cannot start their behavior modification under pressure. Meanwhile, in the long and tedious intervention, they should find the delights and have strong motivation, and it is better they can even take the initiative to complete the tasks and enjoy the process of self-improvement.	Provide a social serious game to motivate children to learn and participate in the intervention. OB CITY uses the interactive multimedia, creates a life simulation game in the children end to let children participate actively in the behavior modification to develop healthier habits, and access some obesity-related knowledge through playing games. In the children end, every child can create a self-designed avatar and keep pets in the game. Children do the game tasks in the real life to modify their behavior, and gain game experience and coins, to make their avatar more powerful and wealthy in the game. To look after their pets, children need to know to modify the pets’ diet and exercise to let their pets be healthy and strong, and they also improve their nutrition and sport knowledge in this operation. OB CITY creates an important virtual character, the “mayor” of the city, who conveys all tasks, reward and punishment to the children. As it is a fictitious character that is extremely powerful for the children in the game, it will provide a greater sense of mission to children and let them be more active in doing tasks and get more sense of honor when they get a reward. In the OB CITY, some children’s information can be shared, ranked and organized in the social network, children can see the others’ information, they can make friends, perform tasks together and compete with each other, they will be involved in the game more actively, and execute tasks aiming to develop a healthy lifestyle. With the social network, children can be more motivated and actively participate in the intervention.
3.2 Children have good knowledge on healthy habits To let the children know the reasons, methods, and objectives of behavior modification is better than just let them change their behavior, so that they can modify behavior spontaneously without relying on the help of their parents or other adults. To know how to determine good or bad behavior, and know how to build a good behavior they have to learn the difference between the different eating habits, know the nature of different foods, and they have to understand the pros and cons of different exercise habits, which includes facts on nutritionand sport. Children develop a habit of correcting behavior themselves, which not only can play a significant role in the behavior intervention, while it will bring several benefits for their after life, and even affect their children.
3.3 Children have good self-control and self-confidence Obese children usually have developed a lot of bad habits in a long period of time. These habits have been deeply integrated into their lives, sicne they cannot control themselves or they cannot avoid the temptation, they could show also this bad behavior again during the process of behavior modification. Moreover, the tasks in the intervention plan are challenges for the children. Some obese children have different degrees of psychological problems [53], [60], they do not have confidence and have a great negative emotion; it is easy to evade the issue when they face the difficulty, and it will lead to failure of the intervention. Hence, children should have a good self-control, to be able to concentrate on the task and not to be subjected to external interference. Meanwhile, they need to establish their self-confidence through a variety of methods, so that they believe they are excellent and they can solve the difficulties they face, so that they have a strong determination to achieve the intervention.	Establish a comfortable environment As mentioned before, OB CITY uses several affective computing techniques to detect children’s emotion state, to try to maintain children’s psychological balance, to reduce the influence of affective factors to the childhood obesity treatment. Children need to do tests before entering the OB CITY system, which include several psychological questions, to obtain children’s initial psychological assessment. Meanwhile, OB CITY is designed as a life simulation game, the behavior and performance (career choices, color preferences, and dialogue) of children’s avatar in the game can be used to realize the data mining, and the result like children’s personality and emotion state may be mapped to children’s mental state in real life. In addition to obtaining information directly from children, OB CITY utilizes the parents’ observations and feelings, to be a reference of the detection of children’s emotion. Apart from adjusting the behavior modification plan according to children’s state, OB CITY will give to others feedback. The utterance of the game will be changed depending on children’s emotion, to make more effective to convey meaning. Children will note the difference of the system and feel more comfortable and respected.