Our study showed that weight loss recommendations based on quantitative and qualitative food targets and a reduction in sedentary behavior yielded weight loss over 12 months of follow-up. Lifestyle interventions are the predominant recommendation for childhood and adolescent weight loss, and those who prioritize nutritional counseling and increases in physical activity - with favorable changes in EB - have been successful with weight loss and maintenance as adults (11).
Lang and Froelicher (2006) suggest that promoting healthier eating habits and reducing sedentary behavior yield favorable change in EB (12). The consumption of foods rich in simple carbohydrates and saturated and trans fats cause changes in steady- state in fasting. Therefore, we can infer that our cohort may have reduced their intake of foods that increase blood glucose levels, insulin and TG. The EB of an obese individual may be connected to easy access to energy-dense and highly palatable foods. During follow-up with patients, reductions intake in sugar, fat and ultra processed foods were emphasized. Studies have shown that reducing intake of sweetened beverages is associated with a decrease in child and adolescent overweight, and that reducing consumption of fast foods is promising for weight loss (13,14).
Our results may suggest that the stage of lipolysis may be related to a favorable change in EB because participants display more self-control (CR) and less EE when serum levels of insulin, glucose and TG are reduced. According to Maclean et al. (2011), a decline in fasted insulin is evidence of weight loss and calorie restriction. Schwartz et al. (1997) indicate that the weight loss is characterized by low levels of insulin (15,16). Brogan et al. (2012) argue that CR can be a successful strategy for weight loss (17).
The amount of weight loss needed to improve the quality of life of obese adolescents has not been established. However, studies show that a reduction in BMI z-score score > 0.5 reduces cardiovascular risk factors and insulin resistance (18). Even with modest weight loss, the intervention had a significant impact on the overall health of these adolescents.
For Keränen et al. (2009), changes in EB do not depend on whether the recommendations are intensive or short-term (19). Our findings showed significant results after 12 months of follow-up, corroborating findings from other interventions with 6–12 months of follow-up (20).
Reduced BMIs were associated with changes in circulating levels of PYY. The present study shows that PYY reduces in concomitance with weight loss or with food restriction.These; findings corroborate other studies claiming that PYY helps reduce appetite, body weight and adiposity (21, 22). Although we have no significant association between WC, TC and TG with PYY, the lowering of these parameters over time suggests a reduction in cardiometabolic risk for adolescents (23).
TFEQ-21 is more often used in adults than in obese adolescents. Studies in adults have shown that the high susceptibility to overeat (uncontrolled eating) combined with low CR is associated with increased body weight (24). Our research found no significant association between BMI and UE and CR behaviors, but we did find that those with lower UE and higher CR had better glucose results over the 12 month follow-up.
Contrary to studies by Hainer et al. (2006) and Bryant et al., (2008) we found no significant association between UE, CC, EE, BMI and other anthropometric parameters (25,26). We assume that the absence of a correlation is due to the sample size, because UE and EE scores decreased among male and female participants while CR scores increased. Higher CR scores increases the likelihood of weight loss maintenance in individuals with excess weight (19).
Our study found no associations between the biological responses of the PYY hormone and the behavioral phenotypes UE, CR and EE, but we did see a favorable change in ED over 12 months. The adolescents in our study acquired a more controlled EB over 1 year. According to some studies, individuals with UE and EE are unsuccessful in weight loss and maintenance (19, 27).
Food intake is regulated by glucose, amino acids, hormones and neuropeptides. Insulin signals adiposity within the brain and in central nervous system influencing energy homeostasis through food intake and body weight (28). Adipose tissue increases the demand for insulin and, in obese patients, can cause heightened levels of blood glucose, favoring lipogenesis. Patients who decreased their UE and EE scores the most were, respectively, those who lowered their serum levels of insulin and glucose the most. The patients who lowered their insulin and TG the most were those who increased their CR score the most.
An increase in CR score can denote self-control over food intake. However, we should emphasize that our results on EB do not imply causality; although it is possible to infer that CR, UE and EE behaviors have an impact on food intake and weight loss.