Effect of Mindfulness on Stress, Appetite Hormones and Body Weight of Obese Schoolchildren. Controlled Clinical Trial

Parents of children 10-14 years of age with suspected obesity will be invited to participate. When the child and at least one of the parents wish to participate, anthropometry will be performed to calculate the BMI z-score and the Spence questionnaire will be applied to identify stress. If they meet the selection criteria, they will be recorded in a pre-registration form to call them once the sample size is completed in order to start the interventions simultaneously for all the children and in parallel for the two groups. To initiate the intervention, the children will be summoned in the Research Unit accompanied by at least one of the parents at 7:00 with at least eight hours of fasting, without brushing their teeth and without having performed any physical activity, for explain what their participation in the study consists of and ask them to sign the letters of consent and informed consent. Anthropometric measurements (weight, height, waist circumference) will be taken, and a peripheral blood sample will be taken to determine the concentrations of insulin, glucose, leptin and ghrelin, and a 24-h reminder questionnaire will be applied. When they leave, they will be given a kit for collecting saliva samples to calculate the Cortisol Awakening Response and will be given the appropriate instructions. Once all the children's anthropometric and diet information has been obtained, they will be randomly assigned to one of the two groups using a computerized random number table. The children assigned to the mindfulness group will be summoned every Wednesday in the classroom of the Research Unit to receive the sessions, which will be taught by an expert in mindfulness techniques in children of the Spanish School of Transpersonal Development. Children assigned to the conventional treatment group will be summoned every Thursday at the same place to receive reinforcement talks aimed at motivating the child and their parents to adhere to the indications of diet and physical activity, taught by a pediatric endocrinologist with nutrition training. involved in the investigation. Body weight will be measured every week before the session, and biochemical measurements will be repeated at the end of the eight weeks of intervention and eight weeks after the end of the intervention to assess relapses.