Gender specific effects on human eating have been previously reported. Here we investigated sex-based differences in neural activation via whole-brain blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) in response to high energy-dense (high-ED) vs. low-ED visual and auditory food cues in obese men vs. women in both fed and fasted states. The results show that in response to high vs. low ED foods in the fed state, obese men (vs. women), had greater activation in brain areas associated with motor control regions (e.g. supplementary motor areas) whereas women showed greater activation in cognitive-related regions. When fasted, obese men had greater activation in a visual-attention region whereas obese women showed greater activation in affective and reward related processing regions (e.g. caudate). Overall the results support our a priori hypothesis that obese women (vs. men) have greater neural activation in regions associated with cognition and emotion-related brain regions. These findings may improve our understanding of sex specific differences among obese individuals in eating behavior.

Sexually-dimorphic behavioral and biological aspects of human eating have been described. Using psychophysiological interactions (PPI) analysis, we investigated sex-based differences in functional connectivity with a key emotion-processing region (amygdala, AMG) and a key reward-processing area (ventral striatum, VS) in response to high vs. low energy-dense (ED) food images using blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) in obese persons in fasted and fed states. When fed, in response to high vs. low-ED food cues, obese men (vs. women) had greater functional connectivity with AMG in right subgenual anterior cingulate, whereas obese women had greater functional connectivity with AMG in left angular gyrus and right primary motor areas. In addition, when fed, AMG functional connectivity with pre/post-central gyrus was more associated with BMI in women (vs. men). When fasted, obese men (vs. women) had greater functional connectivity with AMG in bilateral supplementary frontal and primary motor areas, left precuneus, and right cuneus, whereas obese women had greater functional connectivity with AMG in left inferior frontal gyrus, right thalamus, and dorsomedial prefrontal cortex. When fed, greater functional connectivity with VS was observed in men in bilateral supplementary and primary motor areas, left postcentral gyrus, and left precuneus. These sex-based differences in functional connectivity in response to visual food cues may help partly explain differential eating behavior, pathology prevalence, and outcomes in men and women.

Purpose To assess night eating syndrome (NES) in patients referred for polysomnography and its association with obstructive sleep apnea (OSA). We also assessed whether participants with OSA were more likely to get up and eat at night, and whether these behaviors were associated with the apnea-hypopnea sleep index (AHI). We additionally examined whether NES and OSA were associated with BMI, and assessed depressed mood among participants with NES or OSA. Methods The Night Eating Diagnostic Questionnaire (NEDQ), Zung Depression Scale, and demographic and medical questionnaires were used to evaluate 84 qualified participants. Polysomnography was used to assess AHI, and therefore OSA. Results Thirty individuals met full or sub-threshold NES (NES[St]) criteria, and 54 had no night eating (Normal). Eighty-nine percent of the sample had OSA with AHI ≥ 5. Neither AHI nor BMI differed between NES(St) and Normal, F(1,82)=1.67, p=.20 and F(1, 82)=2.2, p =.14, respectively. Participants with NES(St) were, however, more likely than Normal to have depressed mood (mild, moderately, or severely depressed), χ2=4.47 p=.03. There was a positive correlation between AHI and BMI, r=.37, p=.001. Those with OSA were not more likely to eat at night, F(1,82) = .04, p = .84, or get out of bed more often, F(1,13) = .23, p = .64, and there was no correlation between AHI and eating at night (r = −.11, p = .31). However, there was a positive correlation between AHI and the number of times participants got up out of bed (r = .81, p < .001). Conclusions We found that NES was not associated with BMI or AHI severity. The findings show that NES is primarily an eating disorder, rather than a sleep disorder, and that there is an association between NES and depressed mood.