Our main goal was to identify associations (linear and quadratic) of BMI and characteristics of eating behavior (CR, DIS) with BOLD activation during volitional regulation of food craving. We tested separate regression models to individually assess the relationship of BMI, CR, DIS or regulation success and the respective regulation contrasts (REGULATE_TASTY>ADMIT_TASTY, REGULATE_TASTY>REGULATE_NOT_TASTY) including age (analyses of BMI, CR, DIS, regulation success) or age and BMI (analysis of BMI 2 ) as covariates. To assess the relationship of craving intensity and appetitive brain activity, separate regression models were tested on the respective craving contrasts (ADMIT_TASTY>REGULATE_TASTY, ADMIT_TASTY>ADMIT_NOT_TASTY). Please see Supplementary Table III for a summary of performed regression analyses. Second-level maps were thresholded voxelwise at P<0.001 and corrected for multiple comparisons at a cluster threshold of P<0.05 (family-wise error) for the whole brain.
Functional contacts studies
Functional connectivity was assessed by means of psychophysiological interaction (PPI) analysis. 28 Source regions were based on the above-mentioned regression analysis of BOLD activation and BMI, our primary research focus. Individual BOLD signal time series within 4-mm spheres surrounding detected peak coordinates were extracted (based on the inverted U-shaped relationship of BMI and REGULATE_TASTY>ADMIT_TASTY, please see ‘Abilities’ section and Table 2 for details). General linear models were estimated separately for every source region including the following regressors: Time course of the respective source region (physiological vector), a vector coding for the main effect (psychological vector; REGULATE_TASTY>ADMIT_TASTY; with the former term weighted as +1 and the latter one weighted as ?1), and the PPI term (element-by-element product between the time course of the source region and the vector coding the main effect). The models also included realignment parameters as nuisance regressors. Single-subject contrasts for the PPI regressors were calculated. In the second-level analysis, we aimed to identify regions whose functional connectivity was related to BMI (linear and quadratic) or characteristics of eating behavior (CR, DIS). Therefore, the PPI terms were regressed on these measures in separate multiple regression analyses. Second-level models also included the regressors of no interest mentioned under subsection ‘Analysis of BOLD response’. Second-level maps were thresholded voxelwise at P<0.001 and corrected for multiple comparisons at a cluster threshold of P<0.05 (family-wise error) for the whole brain. Clusters were considered to be significant at P<0.017 (Bonferroni adjustment to account for the number of investigated seeds). Please see Supplementary Table III for a summary of performed regression analyses.
Results
I seen a strong self-confident relationship out-of Bmi and you may DIS (R dos =0.285, P>0.001, Pearson Birmingham sugar baby correlation, Secondary Profile Ia). Multiple regression study revealed a terrible connection away from Bmi dos having CR (Roentgen dos =0.151, P=0.038, covariate Body mass index; Second Profile Ib), exhibiting an upside down You-shaped dating. Craving strength don’t associate which have Body mass index (R=?0.206, P=0.185, Pearson correlation). We receive a trend of a negative correlation anywhere between controls achievements and you will Bmi (R=?0.295, P=0.055, Pearson relationship). Come across Dining table step one to possess descriptive statistics.
Actions
To control its desire, the professionals (especially overweight volunteers) imagined new negative much time-title consequences from dinner new illustrated palatable dining. Really professionals turned between more controls strategies in the course of the check out (come across Additional Table IV to own informative data on method have fun with). When taught so you can know, all people imagined preference otherwise texture of the displayed food items.
Matchmaking anywhere between Committed pastime and Body mass index, dining behavior, urge strength otherwise subjective control success
Activity in a cluster comprising left putamen, amygdala and insula was nonlinearly (inverted U-shaped) related to BMI during volitional regulation devoid of craving influences (REGULATE_TASTY>ADMIT_TASTY; Table 2, Figure 2). Activation during regulation specific to hedonic food (REGULATE_TASTY>REGULATE_NOT_TASTY) was unrelated to BMI. We found no linear relationships with BMI. Craving intensity correlated positively with activity in the right hippocampus/amygdala during craving devoid of volitional regulatory influences (ADMIT_TASTY>REGULATE_TASTY; Table 2, Supplementary Figure X), but did not correlate with activation during craving specific to hedonic food (ADMIT_TASTY>ADMIT_NOT_TASTY). Neither subjective regulation success nor measures of eating behavior were significantly related to task-related BOLD activity. The above-mentioned results indicate some lateralization of the findings. However, when a less strict threshold was applied, bilateral BOLD activation of all mentioned regions associated with BMI and craving intensity was observed (relationship of BOLD and BMI: t-values thresholded at P<0.05, uncorrected; relationship of BOLD and craving intensity: t-values thresholded at P<0.001, uncorrected).