Increased sensitivity to food cues in the fasted state and decreased inhibitory control in the satiated state in the overweight.
BACKGROUND
Flexibility of food reward-related brain signaling (FRS) between food and nonfood stimuli may differ between overweight and normal-weight subjects and depend on a fasted or satiated state.


OBJECTIVE
The objective was to assess this flexibility in response to visual food and nonfood cues.


METHODS
Twenty normal-weight [mean ± SEM BMI (in kg/m(2)) = 22.7 ± 0.2; mean ± SEM age = 22.4 ± 0.4 y] and 20 overweight (BMI = 28.1 ± 0.3; age = 24.0 ± 0.7 y) participants completed 2 fMRI scans. Subjects arrived in a fasted state and consumed a breakfast consisting of 20% of subject-specific energy requirements between 2 successive scans. A block paradigm and a food > nonfood contrast was used to determine FRS.


RESULTS
An overall stimulus × condition × subject group effect was observed in the anterior cingulate cortex (ACC) (P < 0.006, F((1,38)) = 9.12) and right putamen (P < 0.006, F((1,38)) = 9.27). In all participants, FRS decreased from the fasted to the satiated state in the cingulate (P < 0.005, t((39)) = 3.15) and right prefrontal cortex (PFC) (P < 0.006, t((39)) = 3.00). In the fasted state, they showed FRS in the PFC (P < 0.004, t((39)) = 3.17), left insula (P < 0.009, t((39)) = 2.95), right insula (P < 0.005, t((39)) = 3.12), cingulate cortex (P < 0.004, t((39)) = 3.21), and thalamus (P < 0.006, t((39)) = 2.96). In the satiated state, FRS was limited to the left insula (P < 0.005, t((39)) = 3.21), right insula (P < 0.006, t((39)) = 3.04), and cingulate cortex (P < 0.005, t((39)) = 3.15). Regarding subject group, in the fasted state, FRS in the ACC was more pronounced in overweight than in normal-weight subjects (P < 0.005, F((1,38)) = 9.71), whereas in the satiated state, FRS was less pronounced in overweight than in normal-weight subjects in the ACC (P < 0.006, F((1,38)) = 9.18) and PFC (P < 0.006, F((1,38)) = 8.86), which suggests lower inhibitory control in the overweight.


CONCLUSIONS
FRS was higher in the overweight in the satiated state; however, when sufficiently satiated, the overweight showed decreased inhibitory control signalling, which facilitates overeating. This trial was registered in the Dutch clinical trial register as NTR2174.
Maastricht University Medical Centre, Department of Human Biology, Maastricht, Netherlands. mieke.martens@maastrichtuniversity.nl
Mieke J I
MJ
Martens
Juriaan M
JM
Born
Sofie G T
SG
Lemmens
Leila
L
Karhunen
Armin
A
Heinecke
Rainer
R
Goebel
Tanja C
TC
Adam
Margriet S
MS
Westerterp-Plantenga
D000328:Adult; D015992:Body Mass Index; D062408:Breakfast; D002540:Cerebral Cortex / Q000502:physiology; D003463:Cues; D005215:Fasting / Q000502:physiology*; D005260:Female; D005502:Food; D006801:Humans; D006815:Hunger / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D050177:Overweight / Q000628:therapy*; D017397:Prefrontal Cortex / Q000502:physiology; D012201:Reward; D012527:Satiation / Q000502:physiology*; D011795:Surveys and Questionnaires; D055815:Young Adult