Dietary Restraint Related to Body Weight Maintenance and Neural Processing in Value-Coding Areas in Adolescents.

Abstract

There is an alarming increase in the obesity prevalence among children in an environment of increasing availability of preprocessed high-calorie foods. However, some people maintain a healthy weight even in such obesogenic environments. This difference in body weight management could be attributed to individual differences in dietary restraint; however, its underlying neurocognitive mechanisms in adolescents remain unclear. This study aimed to elucidate these neurocognitive mechanisms in adolescents by examining the relationships between dietary restraint and the food-related value-coding region located in the ventromedial prefrontal cortex (vmPFC). The association between dietary restraint and BMI was tested using a multilinear regression analysis in a large early adolescent cohort (n=2554; age, 12.2± 0.3 years; BMI, 17.9± 2.5kg/m2; 1354 boys). Further, an fMRI experiment was designed to assess the association between the vmPFC response to food images and dietary restraint in 30 adolescents (age, 17.6± 1.9 years; BMI, 20.7± 2.2kg/m2; 13 boys). Additionally, using 54 individuals from the cohort (age, 14.5± 0.6 years; BMI, 18.8± 2.6kg/m2; 31 boys), we assessed the association between dietary restraint and intrinsic vmPFC-related functional connectivity. In the cohort, adolescents with increased dietary restraint showed a lower BMI (β = -0.38; P <0.001; B = -0.06; SE=0.003). The fMRI results showed a decreased vmPFC response to high-calorie food were correlated with greater dietary restraint. Moreover, there was an association of attenuated intrinsic vmPFC-related functional connectivity in the superior and middle frontal gyrus and the middle temporal gyrus with greater dietary restraint. Our findings suggest that dietary restraint in adolescents could be a preventive factor for weight gain; its effect involves modulating the vmPFC, which is associated with food value coding.