Increased dorsolateral prefrontal cortex activation in obese children during observation of food stimuli

Abstract

Objective: Food cues yield different patterns of brain activation in obese compared with normal-weight adults in prefrontal and limbic/paralimbic areas. For children, no mapping studies comparing representation sites for food and other stimuli between obese and normal-weight subjects are available. Design: We used a cross-sectional design of two age-matched subject groups to investigate differences in brain activation in response to visually presented food, pleasant, and neutral pictures between obese/overweight and normal children. Subjects: 22 overweight/obese children were compared with 22 normal-weight children. Measurements: Functional magnetic resonance imaging (of the whole head during perception of visually presented stimuli), psychological testing, and psychophysical measures of heart rate deceleration were assessed. Results: Obese children showed higher activation of the dorsolateral prefrontal cortex (DLPFC) in response to food pictures. In addition, DLPFC activation was negatively correlated with self-esteem. In contrast, normal-weight children showed higher activation of the caudate and hippocampus specific to food pictures, and of the anterior cingulate cortex and thalamus to visual cues in general. In response to food stimuli, obese children showed a heart rate deceleration correlating positively with activation of the ventrolateral prefrontal cortex. Conclusion: Obese children react to food stimuli with increased prefrontal activation, which might be associated with increased inhibitory control.

The potential role of and deficits in frontal cortical brain areas implicated in executive control of food intake

“…The observations by Hollman et al 3 also confirm earlier observations on the contribution of cortical brain activationrelated ability to inhibit food intake and thereby energy intake. [13][14][15][16][17][18][19] Interestingly, the observations related to obesity, PWS, as well as to dietary restraint, fit well with the suggested bell-shaped reward-addiction-reward-deficiency model. 12,13 Obviously, a possible solution for this, namely dietary restraint behavior, appears to be facilitated by the ability to inhibit, and this ability is related to cortical brain activation.…”

Obese children show hyperactivation to food pictures in brain networks linked to motivation, reward and cognitive control

“…Their hyper-responsiveness to food stimuli might contribute to increased food motivation, increased intake and poor health-related behaviors. Also, as Davids et al 22 suggested, increased activity in the PFC may reflect attempts to control behavior in the context of increased food motivation. Another important distinction between the HW and obese groups was that obese subjects failed to show significant post-meal reduction of activation in the prefrontal, limbic and reward processing (ventral striatum) regions, whereas the HW subjects showed a significant reduction in prefrontal and limbic activity after eating.…”

“…21 A recent study reported that obese children show higher activation of the dorsolateral PFC than HW children, which they hypothesize to be associated with increased inhibitory control in the obese group. 22 These studies suggest that neural networks of food motivation are active in childhood and continue throughout the lifespan, although longitudinal studies are needed to better characterize this process.…”

Fat brains, greedy genes, and parent power: A biobehavioural risk model of child and adult obesity

“…In adolescent girls, Stice et al (2010) reported positive associations between BMI and post-fast responses to appetizing food pictures in the putamen, OFC and frontal operculum. Most recently, Davids et al (2010) described increased dLPFC responses, but lesser caudate and hippocampus responses to food pictures in overweight/obese versus lean 9 -16 year olds. Stice et al (2008b) have also examined responses to conditioned cues signifying imminent milkshake delivery, and have shown greater cueassociated activation in obese versus lean adolescent girls in the anterior and middle insula and somatosensory cortex.…”