Resumen de Childhood obesity: Interrelation among diet quality, lifestyle factors, and obesity
Childhood obesity remains a major public health burden. Understanding and identifying the complex relationship between diet quality and lifestyle factors is important for pediatric weight control and obesity prevention strategies. The main scope of the present thesis was to determine the complex correlation between obesogenic behaviors, diet quality and overweight and obesity in Spanish youth. This thesis is based on data from three studies: i) Enkid, a representative national study of the Spanish population aged 2 to 24 years, n=3534; ii) POIBC, a community based childhood obesity program, including children aged 8 to 10 years, n = 2250. The study was carried out during two school years, 2012 to 2014, with an average follow-up of 15 months; iii) INMA, population-based birth cohort, including children aged 4 years with an average follow-up of 3 years, n= 1480. We found that total flavonoids intake (paper I), meal frequency and physical activity were positively associated with adherence to the Mediterranean diet (paper III), while screen time and external eating were associated with poor adherence (paper III). A high maternal level of education increased the odds of a child adhering to the Mediterranean diet (paper III).We used the diet inflammatory index to explore the association between the inflammatory potential of diet and diet quality (paper II). We concluded that a healthy diet, characterized by high adherence to the Mediterranean diet, high total dietary antioxidant capacity, or low energy density, was linked to greater anti-inflammatory potential of the diet. Finally, in two studies we evaluated the impact of lifestyle obesogenic behaviors on childhood obesity and abdominal obesity. In the first study (paper IV), we defined four obesogenic behaviors as: <1 hour physical activity/day; ≥2 hour/day of screen time; skipping breakfast; and having fewer than 3 meals/day. We found that the concurrence of obesogenic behaviors (high screen time, skipping breakfast, and low physical activity and meal frequency) increased risk of higher Body mass index (BMI) z-scores, higher waist-to-height ratio (WHtR) and higher odds of overweight and abdominal obesity. In addition, high maternal and parental education was associated with decreasing presence of obesogenic behaviors. In the second study (paper V), we constructed a child healthy lifestyle score (CHLS) comprising five target lifestyle behaviors that were either favorable (extracurricular physical activity, sleep time, plant-based food consumption) or unfavorable (television time and consumption of ultra-processed foods).We found that CHLS at age 4 years was negatively associated with BMI, waist circumference (WC) z-scores and higher odds of overweight and obesity at age 7 years. This PhD research shows an increase in BMI among Spanish children with low physical activity, meal frequency, and sleep time, and high TV time and ultra-processed food intake. The findings also highlight an inverse relationship between waist circumference and physical activity, sleep time, whereas skipping breakfast, and TV time were positively associated with WC z-score and increased the odds of abdominal obesity. Maternal educational level determines children’s diet quality, and the presence of obesity lifestyle factors. Our finding highlights several key modifiable behaviors that can be targeted by policies and interventions to improve diet quality and to tackle the childhood obesity problem in Spain.
Keywords: Obesity, childhood obesity, cohort study, diet, inflammation, lifestyle factors
