There is growing evidence of behavioural and neurobiological overlaps between obesity and drug abuse. Reduction of the amplitude of P300, a component of event-related potentials (ERP) elicited by an oddball paradigm, is an electrophysiological characteristic and a marker of vulnerability in substance abuse. We want to determine whether obesity is associated with such electrophysiological features during an auditory oddball paradigm. We postulate that obesity could be associated with electrophysiological abnormalities that could be viewed as a possible vulnerability marker for food addiction.

Inclusion Criteria:

• The inclusion criteria for the study are men and women aged 20-60 years, BMI 18.5-24.9 kg/m2 for control subjects and BMI>30 kg/m2 for obese subjects, stable body weight over the previous 3 months, report of sedentary or moderate physical activity

Exclusion Criteria:

• The exclusion criteria are pregnancy, post-menopausal women, any physiological or psychological illness that could influence the results, subjects likely to take medical drugs interfering with the electrophysiological parameters of the study, diabetes, hearing disorder, intense physical activity and report or evidence of excessive alcohol consumption, depressive state or eating disorders according to Diagnostic and Statistical Manual of Mental Disorders (DSM-IV).

a healthy but normal-weighted or obese population. Depressive state or eating disorders were carefully evaluated.