Background: Insulin resistance is the primary metabolic disorder associated with obesity; yet little is known about its role as a determinant of the metabolic syndrome in obese children. The aim of this study is to assess the association between the degree of insulin resistance and the different components of the metabolic syndrome among obese children and adolescents. Methods: An analytical, cross-sectional and population-based study was performed in forty-four public primary schools in Campeche City, Mexico. A total of 466 obese children and adolescents between 11-13 years of age were recruited. Fasting glucose and insulin concentrations, high density lipoprotein cholesterol, triglycerides, waist circumference, systolic and diastolic blood pressures were measured; insulin resistance and metabolic syndrome were also evaluated. Results: Out of the total population studied, 69% presented low values of high density lipoprotein cholesterol, 49% suffered from abdominal obesity, 29% had hypertriglyceridemia, 8% presented high systolic and 13% high diastolic blood pressure, 4% showed impaired fasting glucose, 51% presented insulin resistance and 20% metabolic syndrome. In spite of being obese, 13% of the investigated population did not present any metabolic disorder. For each one of the components of the metabolic syndrome, when insulin resistance increased so did odds ratios as cardiometabolic risk factors. Conclusions: Regardless of age and gender an increased degree of insulin resistance is associated with a higher prevalence of disorders in each of the components of the metabolic syndrome and with a heightened risk of suffering metabolic syndrome among obese children and adolescents.

Background/Objectives: Omega-3 and omega-9 fatty acid supplementation has shown metabolic and immunomodulatory benefits, but evidence in pediatric insulin resistance is limited, and the persistence of effects after treatment discontinuation remains uncharacterized. This study evaluated the independent and combined effects of omega-3 and omega-9 supplementation on the metabolic and inflammatory profile of children with obesity and insulin resistance, during and after active treatment. Methods: This prespecified secondary analysis of a multicenter, randomized, triple-blind, three-arm parallel trial (NCT05488223) included 97 children (8–17 years) with overweight/obesity and baseline insulin resistance (HOMA-IR > 3.0). Participants received 1.8 g/day of omega-3 (n = 32), omega-9 (n = 34), or combined supplementation (n = 31) for 3 months, followed by a 2-month post-intervention follow-up. Metabolic and inflammatory markers were assessed at baseline (T1), end of treatment (T2), and follow-up (T3). The primary outcome was the change in HOMA-IR from T1 to T2. Results: Active supplementation significantly reduced fasting insulin and HOMA-IR in the Combined (p < 0.001) and Omega-9 (p = 0.010 and p = 0.006) groups; at month 5, only the Combined group maintained significant reductions in both. IL-6 and leptin decreased across all groups during intervention and remained reduced at follow-up. Multivariable regression (n = 96) showed the metabolic response was most strongly associated with baseline metabolic status and concurrent BMI reduction rather than intervention group, which was not an independent predictor of metabolic response, nor consistently of inflammatory outcomes (one exception: a smaller IL-4 increase with omega-9, p = 0.043, unconfirmed in GEE). Conclusions: Within-group reductions in HOMA-IR and fasting insulin persisted after discontinuation only in the Combined group, but without significant between-group differences at any timepoint, consistent with response magnitude reflecting baseline status and adiposity reduction rather than treatment group per se. This positions combined supplementation as a potential metabolic adjuvant—not a standalone therapy—for HOMA-IR-defined insulin resistance in pediatric obesity, assessed here via anthropometric and biochemical rather than imaging-based measures.