Brain response to food cues varying in portion size is associated with individual differences in the portion size effect in children

Abstract

Large portions promote intake of energy dense foods (i.e., the portion size effect--PSE), but the neurobiological drivers of this effect are not known. We tested the association between blood oxygen level dependent (BOLD) brain response to food images varied by portion size (PS) and energy density (ED) and children's intake at test-meals of high- and low-ED foods served at varying portions. Children (N = 47; age 7-10 years) participated in a within-subjects, crossover study consisting of 4 meals of increasing PS of high- and low-ED foods and 1 fMRI to evaluate food images at 2 levels of PS (Large, Small) and 2 levels of ED (High, Low). Contrast values between PS conditions (e.g., Large PS - Small PS) were calculated from BOLD signal in brain regions implicated in cognitive control and reward and input as covariates in mixed models to determine if they moderated the PSE curve. Results showed a significant effect of PS on intake. Responses to Large relative to Small PS in brain regions implicated in salience (e.g., ventromedial prefrontal cortex and orbitofrontal cortex) were positively associated with the linear slope (i.e., increase in intake from baseline) of the PSE curve, but negatively associated with the quadratic coefficient for the total meal. Responses to Large PS High ED relative to Small PS High ED cues in regions associated with cognitive control (e.g., dorsolateral prefrontal cortex) were negatively associated with the linear slope of the PSE curve for high-ED foods. Brain responses to PS cues were associated with individual differences in children's susceptibility to overeating from large portions. Responses in food salience regions positively associated with PSE susceptibility while activation in control regions negatively associated with PSE susceptibility.

Portion size has sustained effects over 5 days in preschool children: a randomized trial

“…However, the lack of a significant change in the trajectory of energy intake when accounting for non-study foods demonstrates the robust effect of portion size on young children's intake. The mechanisms underlying the effect of portion size in children are not clear (38), but may be related to the activation in brain regions associated with reward (39) or the perception that it is appropriate to eat more food when larger portions are served (40). The finding that larger portion sizes led children to eat substantially more than their energy requirements over 5 d indicates that oversized portions can overwhelm a child's regulatory system and that further investigation is needed to identify modifiable mechanisms underlying this effect.…”

A Biopsychosocial Model of Sex Differences in Children’s Eating Behaviors

“…One potential contribution to differences in eating behavior between male and female children is variation in neural processing of food cues. Food cues elicit responses in brain regions implicated in executive function, subjective valuation (e.g., orbitofrontal cortex), and visual processing (e.g., fusiform gyrus) [106] that are correlated with eating behaviors [107,108]. Several studies have observed sex differences in neural response to food cues.…”

A Biopsychosocial Model of Sex Differences in Children’s Eating Behaviors

“…Food cues elicit responses in brain regions and viewed through a mirror mounted on the head coil using a magnet-compatible projector. The protocol for task design and image development has been reported elsewhere 107,115 . In brief, children analyses were then conducted using energy density contrasts (high-ED -low-ED) derived from parameter estimates for each portion size condition separately, as well as a composite (i.e., across both portion sizes).…”

“…21 implicated in executive function, subjective valuation (e.g., orbitofrontal cortex), and visual processing (e.g., fusiform gyrus)105 that are correlated with eating behaviors106,107 . Several studies have observed sex differences in neural response to food cues.…”