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. DESIGN: Twenty normal-weight [BMI (in kg/m(2)) = 22.7 +/- 0.2; 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 x condition x 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.
Martens, M., Born, J. M., Lemmens, S. G., Karhunen, L., Heinecke, A., Goebel, R., Adam, T. C., & Westerterp-Plantenga, M. S. (2013). Increased sensitivity to food cues in the fasted state and decreased inhibitory control in the satiated state in the overweight. American Journal of Clinical Nutrition, 97(3), 471-479. https://doi.org/10.3945/ajcn.112.044024