Obesity is frequently associated with consumption of high amounts of sugar and/or fat. Studies have demonstrated a high prevalence of overweight and obesity associated or not with increase rates of psychiatry disorders, in particular mood and anxiety disorders. Recent works have demonstrated an association between specific genes involved in oxidative stress metabolism and anxiety-like behavior. The aim of this study was to investigate the effect of a highly palatable diet enriched with sucrose in body fat mass composition, anxiety behavior and brain oxidative status. Twenty male Wistar rats received two different diets during four months: standard chow (SC) and highly palatable (HP). Metabolic parameters, behavioral tests and oxidative stress status were evaluated. Body fat mass, insulin sensitivity and glucose tolerance were altered in the HP group (p<0.01). The same group spends less time in light compartment and had a lower risk assessment behavior (p<0.05) but no differences were observed in the open field test habituation (p>0.05). Protein degradation, DCF and TBARS levels were not different in the hippocampus between groups; however, there were higher levels of protein degration in frontal cortex of HP groups (p<0.05), although DCF and TBARS levels don't differ from the SC group (p>0.05). In conclusion, our data suggest that the consumption of HP diet leads to an obese phenotype, increases protein oxidation in frontal cortex and appears to induce anxiety-like behavior in rats.