Food cue-elicited brain potentials in obese and healthy-weight individuals Ilse M.T. Nijs ⁎, Ingmar H.A. Franken, Peter Muris Institute of Psychology, Erasmus University Rotterdam, the Netherlands article info abstract Article history: Received 3 January 2008 Received in revised form 27 May 2008 Accepted 29 July 2008 The main objective of this study was to investigate, by means of event-related potentials (ERPs), whether obese individuals process food-related information differently as compared to normal-weight individuals. Because amplitudes of late positive ERP components (P3, LPP) reflect motivational tendencies, obese participants were expected to display enlarged P3 and LPP amplitudes towards food pictures. Obese and normal-weight adults were exposed to pictures of food and control items, while EEG was recorded. Subjective levels of food craving and hunger were also assessed. While there were no differences in ERP amplitudes between obese and normal-weight individuals, significantly larger P3 and LPP amplitudes were elicited by pictures of food items as compared to control pictures. Positive correlations were found between P3 and LPP amplitudes and self-reported increases of hunger. It was concluded that food-related information is processed differently in the brain as compared to non-food-related information, in a manner that reflects the natural motivational value of food. In the present study, there was no indication of an electrophysiological or subjective hyper-reactivity to food cues in obese adults. © 2008 Elsevier Ltd. All rights reserved. Keywords: Obesity Cue reactivity Event-related potentials P3 Late positive potentials Food craving 1. Introduction In western societies, health organizations raise the alarm because of increasing prevalence rates of overweight (Body Mass Index [BMI] ≥ 25 kg/m 2 ) and obesity (BMI ≥ 30 kg/m 2 ) in the general population. For example, in the Netherlands – where the present study was conducted – an epidemiological study during the period 1998–2001 revealed that 40 to 50% of adults between the ages of 20 and 70 years are overweight, while circa 10% of them are obese (Visscher, Viet, Kroesbergen, & Seidell, 2006). Similar research, conducted between 2002 and 2004, led to the conclusion that about 15% of the Dutch children between 4 and 15 years are overweight, whereas 3% of them can be labelled as obese (van den Hurk et al., 2006). These figures have even doubled since the 1980s, and are expected to double once more in the upcoming two decades if no interventions are undertaken (Bemelmans, Hoogenveen, Visscher, Verschuren, & Schuit, 2004; Schokker, Visscher, Nooyens, van Baak, & Seidell, 2007). In essence, overweight is the result of a chronic imbalance between energy intake and energy expenditure: more kilocalories are ingested than necessary for the body's metabolism. Although this imbalance is the consequence of a complex interplay between genetic– biological and environmental–behavioral factors, it is the environment, promoting an unhealthy lifestyle and ‘obesogenic’ behavior, that is held largely responsible for the dramatic worldwide increase in the prevalence of overweight (Hill & Peters, 1998; Hill, Wyatt, Reed, & Peters, 2003). More precisely, the abundant availability of rewarding, thus high-caloric and palatable, food is emphasized to contribute to overeating behavior (Hill & Peters, 1998; Speakman, 2007; Volkow & Wise, 2005). It has been suggested that there are individual differences in the sensitivity and reactivity to the rewarding properties of environmental food cues (Beaver et al., 2006; Franken & Muris, 2005). In sensitive individuals, the mere exposure to palatable food might induce excessive craving and a tendency to indulge in overeating behavior, even in the absence of physiological hunger or nutritional deficits (Berridge, 2007; Jansen, 1998; Wardle, 1990). Eating Behaviors 9 (2008) 462–470 ⁎ Corresponding author. Institute of Psychology, Erasmus University Rotterdam, Woudestein T12-43, P.O. Box 1738, 3000 DR Rotterdam, the Netherlands. Tel.: +31 10 4082609; fax: +31 10 4089009. E-mail address: nijs@fsw.eur.nl (I.M.T. Nijs). 1471-0153/$ – see front matter © 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.eatbeh.2008.07.009 Contents lists available at ScienceDirect Eating Behaviors