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“Obesity represents a considerable health threat to modern adults and children worldwide (WHO, 2000), and is an independent risk factor for various common diseases (Must et al., 1999). Excessive weight gain commonly originates from an imbalance between expenditure versus intake of energy. Accordingly, the management of obesity, apart from exercise, mainly involves a calorie restricted diet. Furthermore, it has been reported that calorie restriction has an additional effect on lifetime extension in many animal species (Fontana et al., 2010), selleck chemical suggesting that it may also be beneficial for humans. However, efforts to restrict calorie intake are often hampered

in part by distorted appetite (Borer, 2010). In this sense, both mental and physical health might partly depend

on the ability to resist gratification by regulating the appetitive impulse to consume a desirable but unhealthy food. Appetite is controlled not only by homeostatic requirements such as nutritional deficit but also by other factors, including cognition, emotions, and pleasure from food intake (Rolls, 2007). In the homeostatic system, the hypothalamus senses the nutritional state of the body and thereby controls energy intake and expenditure. In contrast, the pleasure obtained from food intake can provide reinforcement for intake exceeding the homeostatic requirements and thereby lead to overindulgence Selleckchem Screening Library in highly palatable foods. This hedonic component of feeding behavior is mediated by reward-related cortical and sub-cortical systems, including the ventral striatum, the ventral tegmental area, and the orbitofrontal cortex (OFC) (Berthoud, 2002, Berthoud, 2004, Berthoud and Morrison, 2008 and Grill and Kaplan, 2002). There is growing evidence suggesting that overeating is related to an imbalance in these homeostatic and hedonic systems. However, little is known about the neural mechanism that allows individuals to consciously suppress eating behavior (Carnell et al., 2012). In previous research on appetite and eating behavior

using psychophysiological parameters, few studies have employed electroencephalography (EEG) and magnetoencephalography (MEG), and those that did employ these modalities focused primarily on the asymmetry ADAMTS5 of prefrontal cortex activation in response to viewing food pictures or that in relation to subjective scores of an overeating scale (Gable and Harmon-Jones, 2008 and Ochner et al., 2009). MEG monitors the electrophysiological rhythms inside the brain by measuring induced electromagnetic fields using electric or magnetic sensors over the scalp surface (Hämäläinen et al., 1993, He, 2004 and Nunez and Srinivasan, 2005); it has an intrinsic high temporal resolution that allows tracking of rapid neurophysiologic processes at the neuronal time scale of milliseconds.