Changes in Obesity-Related Behaviors Following a Multicomponent Intervention (PIMUNIC) Among Seri Indigenous Children

Background/Objectives: The Seri community is undergoing a nutritional transition characterized by changes in its traditional diet. Multicomponent interventions may promote healthier lifestyles. This study aimed to describe the development of a culturally adapted multicomponent intervention (PIMUNIC) and to evaluate changes in obesity-related behaviors and obesity indicators among Seri children at 6 and 12 months. Methods: A single-cohort pre–post intervention was conducted among school-age Seri children. PIMUNIC consisted of 24 weekly educational sessions addressing nutrition, physical activity (PA), and community participation. Anthropometry, body composition, diet, PA, sleep, and nutrition and health knowledge were assessed at baseline, 6 and 12 months. Changes were evaluated using paired t-tests. Results: A total of 122 children participated (97.6% response rate). After 6 months, no favorable changes were observed in obesity indicators, whereas PA changed to +2.61 points, sleep +0.87 h/night, and knowledge +1.72 points. Energy from ultra-processed foods (EUPF), soft drinks and juices changed by −151.24 kcal/day, −127.54 g/day and −73.79 g/day, while plain water increased by +290.86 g/day. At 12 months, changes in PA (3.71 points), knowledge (2.03 h/night), EUPF (−112.34 kcal/day) and juices (−92.29 g/day) were maintained. Conclusions: PIMUNIC was implemented among Seri children and led to changes in obesity-related behaviors after 6 months, some of which were maintained at 12 months, while obesity indicators showed no favorable changes.