Nutrient-based dietary patterns and BMI z-score changes in children and adolescents with obesity after Mediterranean diet intervention

Introduction: Obesity in children and adolescents is a well-known global public health concern. The ability to successfully treat childhood obesity is less than satisfactory, therefore, the development, of cost-effective prevention strategies are of high priority. Hence stands the hypothesis of assessing the baseline dietary intakes to identify at the clinical level which nutrition pattern is associated with a lower response to nutritional intervention. Aim: The aim of this study was to identify nutrient-based dietary patterns in a cohort of children with obesity and the correlation with BMI z-score changes after a behavioural nutritional intervention based on Mediterranean diet. Methods: We enrolled a total of 140 children and adolescents aged 5-15 years old with obesity, defined as >+2 DS BMI-for-age SDS according to WHO reference curves. All children underwent a behavioural nutritional intervention according to Mediterranean Diet Dietary Guidelines, and they were followed from baseline (T0) until follow up (between 6 and 12 months) (T1) by means also of interactive-learning methods. A posteriori dietary patterns were identified through principal component factor analysis performed on 21 nutrients and minerals derived from a food-frequency questionnaire administered at T0 and T1. A linear regression was performed to correlate BMI SDS changes after intervention and nutrient-based patterns. Results: At T1 a significant reduction in BMI SDS, waist-to-height-ratio and HOMA-index were found compared to T0 (p<0.01, paired-t test). The mean change observed in BMI SDS was -0,20±0,38. We identified two main nutrient-based dietary patterns named “Animal proteins, sugars and all lipids” and “vegetable proteins, fibres and iron” (Figure 1). Adherence to the first was significantly associated with a lower BMI SDS change (β coefficient -0,52 (CI -0,996; -0,0521, p value 0,0299), whilst no significant associations were found with the second. Conclusion: Studying the nutrient-based dietary pattern before starting the nutritional intervention could be predictive of the level of success and help identify children with obesity at risk of failure during nutritional intervention.