Attentional impulsivity in binge eating disorder modulates response inhibition performance and frontal brain networks.

BACKGROUND: A subgroup of overweight and obese people is characterized by binge eating disorder (BED). Increased impulsivity has been suggested to cause binge eating and subsequent weight gain. In the current study, neuronal correlates of increased impulsivity in binge eating disorder during behavioral response inhibition were investigated. METHODS: Magnetic brain activity and behavioral responses of 37 overweight and obese individuals with and without diagnosed BED were recorded while performing a food-related visual go-nogo task. Trait impulsivity was assessed with the Barratt Impulsiveness Scale (BIS-11). RESULTS: Specifically, increased attentional impulsiveness (a subscale of the BIS-11) in BED was related to decreased response inhibition performance and hypoactivity in the prefrontal control network, which was activated when response inhibition was required. Furthermore, participants with BED showed a trend for a food-specific inhibition performance decline. This was possibly related to the absence of a food-specific activity increase in the prefrontal control network in BED, as observed in the control group. In addition, an increase in activity related to the actual button press during prepotent responses and alterations in visual processing were observed. CONCLUSIONS: Our results suggest an attentional impulsiveness-related attenuation in response inhibition performance in individuals with BED. This might have been related to increased reward responsiveness and limited resources to activate the prefrontal control network involved in response inhibition. Our results substantiate the importance of neuronal markers for investigating prevention and treatment of obesity, especially in specific subgroups at risk such as BED.

Working memory-related brain activity is associated with outcome of lifestyle intervention.

OBJECTIVE: Lifestyle interventions including reduction of caloric intake are still the most pursued option to treat obesity. However, their outcome in terms of weight loss strongly differs between participants. In our study, we hypothesized that initial differences in brain activation in a food specific memory task are associated with weight change during a lifestyle intervention. DESIGN AND METHODS: Magnetic brain activity was recorded during a one-back visual memory task with food and nonfood pictures in 33 overweight and obese subjects before they underwent a lifestyle intervention. The intervention lasted 6 months and aimed for a reduction in daily caloric intake by 400 kcal. Body mass index (BMI) was determined before and after the intervention. RESULTS: Differences between outer tertiles representing people who increased their BMI by 1.4% ± 1.1% (non-responders) and who reduced their BMI by -6.9% ± 2.6% (responders) are reported. Neuronal activity was related to BMI change in sensor and source space. Non-responders showed higher activation in right inferior frontal and left occipital visual areas, whereas responders showed increased activation in right temporal areas including hippocampus and fusiform gyrus. CONCLUSIONS: Differences in the cerebral response during a food specific memory task indicate an altered cognitive control over food intake. These differences might determine the ability to eat less and successfully lose weight.