title: Dietary restriction in obese children and its relation with eating behavior, fibroblast growth factor 21 and leptin: a prospective clinical intervention study.
abstract: BACKGROUND
  Obesity is significant problem involving eating behavior and peripheral metabolic conditions. The effect of carbohydrate and fat restriction on appetite regulation, fibroblast growth factor 21 (FGF21) and leptin in children has not been defined. Our objective was to compare the effect of both diets.
  
  
  METHODS
  One hundred and twenty children with body mass index (BMI) higher than the equivalent of 30 kg/m(2) for an adult, as corrected for gender and age were randomly assigned to (n = 60) a low-carbohydrate (L-CHO) diet or (n = 60) a low-fat (L-F) diet for 2 months. Fifty-three (88.3 %) subjects on the low-carbohydrate-diet and 45 (75 %) on the low-fat diet completed the study. Anthropometric measures, leptin and FGF21 levels were measured before and after the intervention. Comparison of the data for both of the diet groups was carried out using the t-test for independent variables. Intragroup comparisons before and after of each of the dietary treatments were performed using ANOVA for repeated measures. Factors associated with FGF21, leptin levels and satiety, were analyzed by multiple regression.
  
  
  RESULTS
  After both of the diets, weight, leptin, food responsiveness, and enjoyment of food significantly decreased and high density lipoprotein cholesterol (HDL) increased, but FGF21 decreased. Before and after both of the interventions FGF21 was associated with triglycerides. Before the diet, satiety was associated with lower screen time (p < 0.04) and insulin levels (p < 0.05).
  
  
  CONCLUSIONS
  Both dietary restrictions improved the metabolic and hormonal parameters of obese children. FGF21 is an indicator of a beneficial metabolic response in younger children. After 2 months an adaptation of the eating behavior to food restriction was observed.
authors.affiliation: Department of Medical Sciences, University of Guanajuato, Campus León. 20 de Enero 929. Col Obregón, León Gto, México 37320.
authors.forename: Lorena Del Rocío
authors.initials: Ldel R
authors.lastname: Ibarra-Reynoso
authors.affiliation: Department of Medical Sciences, University of Guanajuato, Campus León. 20 de Enero 929. Col Obregón, León Gto, México 37320.
authors.forename: Liudmila
authors.initials: L
authors.lastname: Pisarchyk
authors.affiliation: Department of Medical Sciences, University of Guanajuato, Campus León. 20 de Enero 929. Col Obregón, León Gto, México 37320.
authors.forename: Elva Leticia
authors.initials: EL
authors.lastname: Pérez-Luque
authors.affiliation: Department of Medical Sciences, University of Guanajuato, Campus León. 20 de Enero 929. Col Obregón, León Gto, México 37320.
authors.forename: Ma Eugenia
authors.initials: ME
authors.lastname: Garay-Sevilla
authors.affiliation: Department of Medical Sciences, University of Guanajuato, Campus León. 20 de Enero 929. Col Obregón, León Gto, México 37320.
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Malacara