Objectives. To assess the effectiveness of a programmed family/group intervention to reduce weight in the treatment of obesity in children 7 to 12 years old in front of usual treatment. Design. Cluster randomized controlled trial, multicenter. Location. Primary health care centers. Participants. Obese children 7 to 12 years old of primary health care centers. Body mass index (BMI) > P 97. Patients give Informed consent. Sampling. Randomized cluster assigned. Assignation unit: primary care center. Analysis unit. Patient (Children and childminder). Size: 280 patients (140 by group). Principal measurements Variables.BMI z score (BMI-SDS) after the 6 month intervention and after 12 -month follow-up. Secondary Measurements Variables. quality of Mediterranean diet, Brief questionnaire of physical activity in children. Brief Physical Activity Assessment Tool (BPAAT) for adults (Parents) , apgar-family questionnaire. sociocultural level., educational level, Gender. Age. BMI parents, family antecedent. Analysis: Primary effectiveness. Initial comparability of groups according to the outcome and confusion variables. Mean differences in z score of BMI with 95% confidence intervals, between groups and generation of a multivariate and multilevel model. Analysis by intention to treat.

This clinical trial aims to evaluate the effectiveness of a family intervention to reduce obesity in children. Overweight and obesity, as defined by the World Organization of Health (WHO) as abnormal or excessive fat accumulation that can be harmful to health, they are considered by this body as one of the most important public health problems of the century XXI, which is the fifth leading death risk factor in the world.

OI has been associated with high co-morbidity in adulthood. The percentile increase in body mass index (BMI) in OI increases the incidence of cases of hypertension , dyslipidemia, left ventricular hypertrophy, atherosclerosis, metabolic syndrome, type 2 diabetes, sleep disorders, as well as psychological effects, such as stigmatization, discrimination, depression and emotional trauma. Obesity in childhood also substantially increases the risk of being an obese adult. In addition, childhood obesity is an independent risk factor for obesity in adulthood. Criteria favorable to therapeutic intervention in cases of obesity are based on the demonstration that with a moderate weight loss (5-10%) can achieve a marked improvement in the associated comorbidity and quality of life even in severe obesity. The prevalence of multiple risk factors increases as the BMI percentile increases, and severe obesity is associated with an increased risk of comorbidity and resistance to sustained weight loss.

The discussion about the relevance and form of the approach to childhood obesity is an open and current issue. A 2007 Cochrane review established that there may be a benefit to behavioral treatment where parents are given responsibility for behavioral change and this is done as a family. To start the intervention, professionals with specific training in physical activity and nutrition applied in childhood, behavioral intervention techniques and promotion of healthy habits in working with families are required.

Another more recent review focused on evaluating the effectiveness of different interventions to treat childhood obesity concludes that although there is not much quality data to recommend a treatment program superior to another, the combined lifestyle and behavior interventions in Comparison with standard care or self-help can lead to a significant reduction in overweight in children and adolescents.

Another aspect to take into account is the relevance of the early intervention of obesity during childhood-adolescence, since it is at this stage that the eating habits and practice of physical exercise are consolidated, in addition to where they conform the personality characteristics of the individual.

The family intervention is proposed as one of the areas most likely to be successful in treating childhood obesity. There are several clinical trials that evaluate different interventions aimed primarily at families and show that they have beneficial effects in the promotion of healthy behaviors related to food and exercise in boys and girls, in addition to highlighting the importance of a combined dietary, behavioral and physical activity component.

The few studies carried out in the specific field of community nursing have small sample sizes and have not shown that the intervention in nursing consultation has been effective as far as weight loss is concerned. Another study comparing the effect of medical counseling and group therapy in childhood obesity concluded that cognitive behavioral therapy is more effective than medical advice and that none of the two treatment improved results compared to the untreated group. There are several limitations that could justify this result, among others the possible insufficient family involvement that is considered of vital importance.

4. 1. CONCEPTUAL Hypothesis : The "Active Families" intervention program is more effective than the usual practice to reduce the weight of children from 7 to 12 years old with obesity at the end of the intervention and at 6 and 12 months after the start of the intervention.

4.2. OPERATIONAL HYPOTHESIS: The "Active Families" family intervention program decreases an average of 0.5 standard deviations plus the BMI of children with childhood obesity than the usual practice at the end of the intervention and at 6 and 12 months after the start of the intervention.

4. 3.OBJECTIVES Main objective: To evaluate the effectiveness of a family intervention program to reduce weight in children aged 7 to 12 years with childhood obesity compared to the usual practice at 6 and 12 months after the intervention.

Secondary Objectives:

1. Evaluate the effectiveness of a family intervention program aimed at children aged 7 to 12 with childhood obesity to improve the quality of food.
2. Evaluate the effectiveness of a family intervention program aimed at children aged 7 to 12 with childhood obesity to increase physical activity.
3. Evaluate the effectiveness of a family intervention program aimed at children aged 7 to 12 with childhood obesity to increase the physical activity of the main caregiver.

Design : Controlled clinical trial with randomized allocation by conglomerates, open, multicenter, 12 months follow-up, in primary care consultations. Location or scope: Health Centers of the Community of Madrid. Duration: 12 months years. Study population : Children diagnosed with obesity attended in primary care consultations of 7 to 12 years of both sexes.

Sample size: It has been estimated for a difference of 0.5 standard deviations ( clinically relevant result ), and a power of 80%. Specifying a total of 170 children, 85 in each group. Correcting for a design effect of 1,369, considering an ICC of 0,041 (28) and an average cluster size of 10 boys or girls, 233 boys or girls are required. Estimating losses of 20%, the final size is 280 children, 140 in each group. Sampling : Randomized allocation by conglomerates (nurses). Randomization unit: Primary Health Care Centers. The Health Centers will be assigned to the intervention or to the control group through a random sequence generated by computer. Analysis Unit: Diads child / caregiver. They will be included by consecutive sampling. During the consultation, that child susceptible to being included in the study will be informed and offered participation. If you agree to participate, you will be asked to complete and sign the informed consent and verify that you meet all the inclusion criteria and none of the exclusion criteria. Randomization of health centers will be carried out once the eligible dyads have been selected for the study, so that the recruitment by professionals is not influenced by the branch of the study to which they have been assigned.

Data Collection :

The information will be collected through clinical interview and physical examination and the data will be recorded in an electronic data collection notebook specially designed for this study. The variables will be collected during 4 visits: at the beginning of the study, at the end of the intervention, at 6 and 12 months.

Losses in participation: Losses and abandonment of follow-up during the study. The cause will be collected (voluntary abandonment, displacement, comorbidity, death and cause). If a patient does not attend a session, at least two telephone contact attempts will be made.

Control group . The activities included in the Service for Childhood Obesity Patients of the Portfolio of Standardized Primary Care Services of the Community of Madrid will be carried out , which establishes a monthly follow-up in the first 6 months and bimonthly from 6 to 12. This consultation will be attended by at least the child and the primary caregiver, the child's educating agent, and will receive supporting documentation for Exercise and strengthen your role.

* Experimental group : Regular intervention plus intervention active families. This intervention, based on the methodology of meaningful learning , it will have two components: group education aimed at parents (caregivers) and education aimed at children in the reviews in consultation. The group intervention will consist of 6 sessions, which with a biweekly / monthly frequency, will be taught as determined in the program monitoring annex, in the 3 months after the initial assessment.

In order to normalize and protocolize the activities in both groups (intervention and control) a training session will be held prior to the start of the field work

Analysis Strategy :

It will be done according to the intention to treat principle.

1. Review of the data and descriptive analysis of the study variables evaluating the normality of the distribution with its corresponding 95% confidence intervals .
2. Initial comparability of the groups according to the outcome and confusion variables . Chi square test for qualitative variables and used the T of Student for quantitative (if they conform to a normal distribution) or nonparametric test (if not follow a normal distribution).
3. Principal effectiveness analysis: calculation of the difference in means of the Z Score between groups, together with their 95% Confidence Interval.
4. To assess the effect of the intervention on the Z score of the BMI, a multivariate analysis will be carried out using a mixed multilevel model (level 1: child / caregiver dyad ; level 2: professional dyad / health center), with the intervention as fixed effects factor and professionals or centers as random effects factor (Brown H and Prescott R (1999). Applied mixed models in medicine. New York: Wiley.).

This same analysis will be applied to analyze the impact of the intervention on the rest of the quantitative dependent variables contemplated in the secondary objectives of the study.

1. - Technical Group.

   • Preparation of the Guide to Attention to Sedentary and Childhood Obesity (Educational Materials of Active Families).
   • Childhood Obesity Care Program (Standardization of the usual service portfolio process in which the standardized care plan for childhood obesity is also included). Presentation of the same to the professionals assigned to the control group through a clinical session of two hours of training.
   • Design of electronic Data Collection Notebook (CRD) accessible from the AP computer HC and a database containing CRD information
   • Periodic monitoring of the information collected: Evolution of patient acquisition and detection of recorded data errors, due to violation of the researcher's manual. For this, the contracted computer technicians will design specific SQL statements (Programming language).
   • Data debugging: validation process by searching for repeated records, and inconsistent, illogical or out of range values.
   • Bibliographic update and management of bibliographic references.

2. - Assistance Group: This group will be formed by nurses and pediatricians of the participating centers. There will be two people responsible for implementing the program in each center that will facilitate contact with the coordinating group. Perform the tasks of the assistance group:

   • Recruitment of patients and assess the inclusion criteria. Carry out the intervention assigned to the patients. Collection and registration of data in the CRD.
   • The professionals of the care group will appear as an attached note in the possible publications derived from the study, so that the names of all the participants appear in the bibliographic databases. Inclusion in these groups will depend on the involvement and activities carried out by each collaborator.

Inclusion Criteria:

• Age: between 7 and 12 years old.
• Obesity: defined by a BMI equal to or greater than P97 for age and sex in the curves and growth charts of the semilongitudinal study by Hernández (1988). Definition recommended by the Clinical Practice Guide of the Ministry of Health. To have primary caregiver.
• Be able to follow the demands of the trial (child and primary caregiver participants).
• Have no intention of moving in the following 12 months. Give informed consent to participate in the study.

Exclusion Criteria:

• Intention of moving in the following 12 months.
• Do not sign informed consent.
• Sensory, psychiatric or occupational limitations of caregivers that do not allow follow-up sessions.

Intervention can't be masked. Statistician conducting the analysis will not know to which study arm a given patient has been assigned.