BackgroundExtreme weight conditions (EWC) groups along a continuum may share some biological risk factors and intermediate neurocognitive phenotypes. A core cognitive trait in EWC appears to be executive dysfunction, with a focus on decision making, response inhibition and cognitive flexibility. Differences between individuals in these areas are likely to contribute to the differences in vulnerability to EWC. The aim of the study was to investigate whether there is a common pattern of executive dysfunction in EWC while comparing anorexia nervosa patients (AN), obese subjects (OB) and healthy eating/weight controls (HC).MethodsThirty five AN patients, fifty two OB and one hundred thirty seven HC were compared using the Wisconsin Card Sorting Test (WCST); Stroop Color and Word Test (SCWT); and Iowa Gambling Task (IGT). All participants were female, aged between 18 and 60 years.ResultsThere was a significant difference in IGT score (F(1.79); p<.001), with AN and OB groups showing the poorest performance compared to HC. On the WCST, AN and OB made significantly more errors than controls (F(25.73); p<.001), and had significantly fewer correct responses (F(2.71); p<.001). Post hoc analysis revealed that the two clinical groups were not significantly different from each other. Finally, OB showed a significant reduced performance in the inhibition response measured with the Stroop test (F(5.11); p<.001) compared with both AN and HC.ConclusionsThese findings suggest that EWC subjects (namely AN and OB) have similar dysfunctional executive profile that may play a role in the development and maintenance of such disorders.

FNDC5/irisin has been recently postulated as beneficial in the treatment of obesity and diabetes because it is induced in muscle by exercise, increasing energy expenditure. However, recent reports have shown that WAT also secretes irisin and that circulating irisin is elevated in obese subjects. The aim of this study was to evaluate irisin levels in conditions of extreme BMI and its correlation with basal metabolism and daily activity. The study involved 145 female patients, including 96 with extreme BMIs (30 anorexic (AN) and 66 obese (OB)) and 49 healthy normal weight (NW). The plasma irisin levels were significantly elevated in the OB patients compared with the AN and NW patients. Irisin also correlated positively with body weight, BMI, and fat mass. The OB patients exhibited the highest REE and higher daily physical activity compared with the AN patients but lower activity compared with the NW patients. The irisin levels were inversely correlated with daily physical activity and directly correlated with REE. Fat mass contributed to most of the variability of the irisin plasma levels independently of the other studied parameters. Conclusion. Irisin levels are influenced by energy expenditure independently of daily physical activity but fat mass is the main contributing factor.

Although the concept of 'food addiction' (FA) has raised growing interest because of evidence for similarities between substance dependence and excessive food intake, there is a lack of studies that explore this construct among the wide spectrum of eating disorders (EDs). Besides providing validation scores of a Spanish version of the Yale FA Scale (YFAS-S), this study examined the prevalence of 'FA' among ED subtypes compared with healthy-eating controls (HCs) and the association between 'FA' scores, eating symptomatology and general psychopathology. A sample of 125 adult women with ED, diagnosed according to Diagnostic and Statistical Manual of Mental Disorders 5 criteria, and 82 healthy-eating women participated in the study. All participants were assessed with the YFAS-S, the ED Inventory-2 and the Symptom Checklist-Revised. Results showed that the internal structure of the one-dimensional solution for the YFAS-S was very good (α = 0.95). The YFAS-S has a good discriminative capacity to differentiate between ED and controls (specificity = 97.6% and sensitivity (Se) = 72.8%; area under receiver operating characteristic curve = 0.90) and a good Se to screen for specific ED subtypes. YFAS-S scores were associated with higher levels of negative affect and depression, higher general psychopathology, more severe eating pathology and greater body mass index. When comparing the prevalence of 'FA' between ED subtypes, the lowest prevalence of 'FA', measured with the YFAS-S, was for the anorexia nervosa (AN) restrictive subtype with 50%, and the highest was for the AN binge-purging subtype (85.7%), followed by bulimia nervosa (81.5%) and binge eating disorder (76.9%). In conclusion, higher YFAS-S scores are associated with bingeing ED-subtype patients and with more eating severity and psychopathology. Although the 'FA' construct is able to differentiate between ED and HC, it needs to be further explored.