Introduction:Obesity risk transmits from parents to children. We investigated underlying neural m... more Introduction:Obesity risk transmits from parents to children. We investigated underlying neural mechanisms by evaluating influences of familial obesity risk defined by maternal obesity, and of current overweight, on three indices of brain structure in adolescents.Methods:Twenty-two lean adolescents with lean mothers (lean low-risk), 25 lean adolescents with mothers with obesity/overweight (lean high-risk), and 36 adolescents with obesity/overweight underwent structural MRI scans for estimation of regional gray and white matter volume and cortical thickness.Results:The lean high-risk compared with the lean low-risk group demonstrated lower gray and white matter volume and cortical thickness in the postcentral gyrus (somatosensory cortex), lower gray and white matter volume in opercular cortex (taste cortex), lower gray matter volume and cortical thickness in the anterior cingulate cortex, and lower cortical thickness in the precuneus. Comparisons of the lean and obesity/overweight groups revealed further structural alterations in postcentral gyrus, posterior cingulate gyrus and middle temporal gyrus.Conclusion:Familial obesity risk and current obesity/overweight were associated with overlapping, and distinct, patterns of brain structure alterations. Longitudinal studies are warranted to investigate whether structural changes associated with familial obesity risk predict future weight trajectories.
Later onset of puberty has been associated with lower body mass index (BMI) in adulthood independ... more Later onset of puberty has been associated with lower body mass index (BMI) in adulthood independent of childhood BMI. However, how the relationship between time of onset of puberty and BMI in adulthood is associated with neurocognitive outcomes is largely unstudied. Here, women were sampled from the Human Connectome Project 1200 PTN release. Inclusion criteria were: 4 (15 minute) resting state fMRI scans, current measured BMI, self-reported age at onset of menstruation (a proxy of age at onset of puberty), and no endocrine complications (e.g., polycystic ovarian syndrome). The effect of age at onset of menstruation, measured BMI at scan date, and the interaction of age at onset of menstruation by BMI on brain functional correlation was modeled using FSLnets controlling for race and age at scan. Corrected significance was set at pFWE<0.05. A final sample of n=510 (age 29.5y±3.6; BMI at scan 25.9±5.6; age at onset of menstruation 12.7±1.6) were included. Age at onset of menstruation was negatively associated with BMI at scan (r=−0.19, p<0.001). The interaction between age at onset of menstruation and BMI at scan was associated with stronger correlation between a somatosensory and visual network (t= 3.45, pFWE= 0.026), and a visual network and cingulo-opercular task control network (t= 4.74, pFWE= 0.0002). Post hoc analyses of behavioral/cognitive measures showed no effect of the interaction between BMI and age at onset of menstruation on behavioral/cognitive measures. However, post hoc analyses of heritability showed adult BMI and the correlation between the visual and somatosensory networks have high heritability. In sum, we show increased correlation between visual, taste-associated, and self-control brain regions in women at high BMI with later age at onset of menstruation
Reinforcement learning guides food decisions, yet how the brain learns from taste in humans is no... more Reinforcement learning guides food decisions, yet how the brain learns from taste in humans is not fully understood. Existing research examines reinforcement learning from taste using passive condition paradigms, but response-dependent instrumental conditioning better reflects natural eating behavior. Here, we examined brain response during a taste-motivated reinforcement learning task and how measures of task-based network structure were related to behavioral outcomes. During a functional MRI scan, 85 participants completed a probabilistic selection task with feedback via sweet taste or bitter taste. Whole brain response and functional network topology measures, including identification of communities and community segregation, were examined during choice, sweet taste, and bitter taste conditions. Relative to the bitter taste, sweet taste was associated with increased whole brain response in the hippocampus, oral somatosensory cortex, and orbitofrontal cortex. Sweet taste was also related to differential community assignment of the ventromedial prefrontal cortex and ventrolateral prefrontal cortex compared to bitter taste. During choice, increasing segregation of a community containing the amygdala, hippocampus, and right fusiform gyrus was associated with increased sensitivity to punishment on the task’s posttest. Further, normal BMI was associated with differential community structure compared to overweight and obese BMI, where high BMI reflected increased connectivity of visual regions. Together, results demonstrate that network topology of learning and memory regions during choice is related to avoiding a bitter taste, and that BMI is associated with increased connectivity of area involved in processing external stimuli. Network organization and topology provide unique insight into individual differences in brain response to instrumental conditioning via taste reinforcers.
The overconsumption of palatable energy-dense foods drives obesity, but few human studies have in... more The overconsumption of palatable energy-dense foods drives obesity, but few human studies have investigated dopamine (DA) release in response to the consumption of a palatable meal, a putative mediator of excess intake in obesity. We imaged [11C]raclopride in the brain with positron emission tomography (PET) to assess striatal dopamine (DA) receptor binding pre- and post-consumption of a highly palatable milkshake (250 mL, 420 kcal) in 11 females, 6 of whom had severe obesity, and 5 of whom had healthy-weight. Those with severe obesity underwent assessments pre- and 3 months post-vertical sleeve gastrectomy (VSG). Our results demonstrated decreased post- vs. pre-meal DA receptor binding in the ventral striatum (p = 0.032), posterior putamen (p = 0.012), and anterior caudate (p = 0.018), consistent with meal-stimulated DA release. Analysis of each group separately suggested that results in the caudate and putamen were disproportionately driven by meal-associated changes in the health...
Obesity can result from excess intake in response to environmental food cues, and stress can driv... more Obesity can result from excess intake in response to environmental food cues, and stress can drive greater intake and body weight. We used a novel fMRI task to explore how obesity and stress influenced appetitive responses to relatively minimal food cues (words representing food items, presented similarly to a chalkboard menu). Twenty-nine adults (16F, 13M), 17 of whom had obesity and 12 of whom were lean, completed two fMRI scans, one following a combined social and physiological stressor and the other following a control task. A food word reactivity task assessed subjective food approach (wanting) as well as food avoidant (restraint) responses, along with neural responses, to words denoting high energy-density (ED) foods, low-ED foods, and non-foods. A multi-item ad-libitum meal followed each scan. The obese and lean groups demonstrated differences as well as similarities in activation of appetitive and attention/self-regulation systems in response to food vs. non-food, and to hig...
ABSTRACTBackground/Objectives We compared neural organization between individuals with recommende... more ABSTRACTBackground/Objectives We compared neural organization between individuals with recommended, high, and very high body mass indexes (BMI). We hypothesized increased segregation of the putamen and cingulate gyrus with increasing BMI, and an increase in integration of the frontal gyrus in the recommended BMI (BMI < 25) group. Subjects/MethodsThis was a cross-sectional, secondary data analysis of the Human Connectome Project data. Independent components of brain regions (nodal) were used to create correlation matrices for the individuals at a recommended BMI (recBMI; n=156), a high BMI (hBMI; 25 < BMI < 30; n=109), and a very high BMI (vhBMI; BMI > 30; n=78). Graph theory-based metrics were calculated at the nodal, functional network, and module levels and compared between groups. ResultsThe hBMI and vhBMI groups exhibited more modules (9 modules) than the recBMI group (8 modules). The vhBMI showed increased integration in the sensory module and higher connectivity be...
Highly palatable, energy-dense (ED), sweet and savory foods may contribute to the obesity epidemi... more Highly palatable, energy-dense (ED), sweet and savory foods may contribute to the obesity epidemic by triggering desire to eat, experienced by some as an addiction-like response. However, individua...
Background: Weight regain is a concerning issue in bariatric patients. We previously demonstrated... more Background: Weight regain is a concerning issue in bariatric patients. We previously demonstrated that taste-related reward processing was associated with six-month weight loss outcomes following Roux-en-Y gastric bypass (RYGB) but not vertical sleeve gastrectomy (VSG). Here, we assessed whether these taste factors persisted in predicting weight loss, and weight regain, at one year post-surgery. Methods: Adult women enrolled in a longitudinal study of taste preferences following bariatric surgery completed behavioral and neuroimaging assessments at one year post-surgery. Results: RYGB produced better weight loss relative to VSG, with weight regain and greater weight loss variability observed from six months to one year post-VSG. Changes in liking for high fat at 2 weeks post-surgery from baseline remained a predictor of weight loss in RYGB, but other predictors did not persist. Average liking ratings rebounded to baseline and higher self-reported food cravings and dietary disinhibit...
Objectives The 2020 dietary guidelines specifically recommended a decrease in sugar intake. Rewar... more Objectives The 2020 dietary guidelines specifically recommended a decrease in sugar intake. Reward-related, brain-based models of overeating and obesity suggest that increased intake of highly palatable foods is linked to decreased dopaminergic (striatal and prefrontal) brain functioning. This reduction acts to increase consumption of food to achieve pleasure. Here, we examined whether increased dietary intake of sugar and fat would be associated with increased activation in reward-related brain regions during anticipation of a sugar sweetened beverage (SSB), but decreased activation during SSB receipt. Methods Young adults (n = 100, age = 21.8 ± 2.4 y, BMI = 23.3 ± 3.5, 70% female) underwent an fMRI scan examining brain responses to receipt of a SSB, a tasteless rinse, and response cue-induced anticipation of these tastes. The Block Food Frequency Questionnaire (FFQ) was used to assess average dietary intake, % daily caloric intake from SSBs, sugar, sugar from SSBs and fat. These w...
Taste sensitivity and liking drive food choices and ingestive behaviors from childhood to adultho... more Taste sensitivity and liking drive food choices and ingestive behaviors from childhood to adulthood, yet their longitudinal association with dietary intake and BMI is largely understudied. Here, we examined the longitudinal relationship between sugar and fat sensitivity, sugar and fat liking, habitual dietary intake, and BMI percentiles in a sample of 105 healthy-weight adolescents (baseline: BMI %tile 57.0 ± 24.3; age 14–16 years) over a 4-year period. Taste sensitivity was assessed via a triangle fat and sweet taste discrimination test. Taste liking were rated on a visual analog scale for four milkshakes that varied in sugar and fat contents (high-fat/high-sugar (HF/HS), low-fat/high-sugar (LF/HS), high-fat/low-sugar (HF/LS), low-fat/low-sugar (LF/LS) milkshakes). A modified version of the reduced Block Food Frequency Questionnaire (BFFQ) was used to assess dietary intake. All measurements were repeated annually. Repeated measures correlations and linear mixed effects models were ...
Identifying correlates of brain response to food cues and taste provides critical information on ... more Identifying correlates of brain response to food cues and taste provides critical information on individual differences that may influence variability in eating behavior. However, a few studies examine how brain response changes over repeated exposures and the individual factors that are associated with these changes. Using functional magnetic resonance imaging, we examined how brain response to a palatable taste and proceeding cues changed over repeated exposures and how individual differences in weight, familial obesity risk, dietary restraint and reward responsiveness correlate with these changes. In healthy-weight adolescents (n = 154), caudate and posterior cingulate cortex (PCC) response increased with repeated cue presentations, and oral somatosensory cortex and insula response increased with repeated milkshake tastes. The magnitude of increase over exposures in the left PCC to cues was positively associated with body mass index percentile (r = 0.18, P = 0.026) and negatively...
Introduction:Obesity risk transmits from parents to children. We investigated underlying neural m... more Introduction:Obesity risk transmits from parents to children. We investigated underlying neural mechanisms by evaluating influences of familial obesity risk defined by maternal obesity, and of current overweight, on three indices of brain structure in adolescents.Methods:Twenty-two lean adolescents with lean mothers (lean low-risk), 25 lean adolescents with mothers with obesity/overweight (lean high-risk), and 36 adolescents with obesity/overweight underwent structural MRI scans for estimation of regional gray and white matter volume and cortical thickness.Results:The lean high-risk compared with the lean low-risk group demonstrated lower gray and white matter volume and cortical thickness in the postcentral gyrus (somatosensory cortex), lower gray and white matter volume in opercular cortex (taste cortex), lower gray matter volume and cortical thickness in the anterior cingulate cortex, and lower cortical thickness in the precuneus. Comparisons of the lean and obesity/overweight groups revealed further structural alterations in postcentral gyrus, posterior cingulate gyrus and middle temporal gyrus.Conclusion:Familial obesity risk and current obesity/overweight were associated with overlapping, and distinct, patterns of brain structure alterations. Longitudinal studies are warranted to investigate whether structural changes associated with familial obesity risk predict future weight trajectories.
Later onset of puberty has been associated with lower body mass index (BMI) in adulthood independ... more Later onset of puberty has been associated with lower body mass index (BMI) in adulthood independent of childhood BMI. However, how the relationship between time of onset of puberty and BMI in adulthood is associated with neurocognitive outcomes is largely unstudied. Here, women were sampled from the Human Connectome Project 1200 PTN release. Inclusion criteria were: 4 (15 minute) resting state fMRI scans, current measured BMI, self-reported age at onset of menstruation (a proxy of age at onset of puberty), and no endocrine complications (e.g., polycystic ovarian syndrome). The effect of age at onset of menstruation, measured BMI at scan date, and the interaction of age at onset of menstruation by BMI on brain functional correlation was modeled using FSLnets controlling for race and age at scan. Corrected significance was set at pFWE<0.05. A final sample of n=510 (age 29.5y±3.6; BMI at scan 25.9±5.6; age at onset of menstruation 12.7±1.6) were included. Age at onset of menstruation was negatively associated with BMI at scan (r=−0.19, p<0.001). The interaction between age at onset of menstruation and BMI at scan was associated with stronger correlation between a somatosensory and visual network (t= 3.45, pFWE= 0.026), and a visual network and cingulo-opercular task control network (t= 4.74, pFWE= 0.0002). Post hoc analyses of behavioral/cognitive measures showed no effect of the interaction between BMI and age at onset of menstruation on behavioral/cognitive measures. However, post hoc analyses of heritability showed adult BMI and the correlation between the visual and somatosensory networks have high heritability. In sum, we show increased correlation between visual, taste-associated, and self-control brain regions in women at high BMI with later age at onset of menstruation
Reinforcement learning guides food decisions, yet how the brain learns from taste in humans is no... more Reinforcement learning guides food decisions, yet how the brain learns from taste in humans is not fully understood. Existing research examines reinforcement learning from taste using passive condition paradigms, but response-dependent instrumental conditioning better reflects natural eating behavior. Here, we examined brain response during a taste-motivated reinforcement learning task and how measures of task-based network structure were related to behavioral outcomes. During a functional MRI scan, 85 participants completed a probabilistic selection task with feedback via sweet taste or bitter taste. Whole brain response and functional network topology measures, including identification of communities and community segregation, were examined during choice, sweet taste, and bitter taste conditions. Relative to the bitter taste, sweet taste was associated with increased whole brain response in the hippocampus, oral somatosensory cortex, and orbitofrontal cortex. Sweet taste was also related to differential community assignment of the ventromedial prefrontal cortex and ventrolateral prefrontal cortex compared to bitter taste. During choice, increasing segregation of a community containing the amygdala, hippocampus, and right fusiform gyrus was associated with increased sensitivity to punishment on the task’s posttest. Further, normal BMI was associated with differential community structure compared to overweight and obese BMI, where high BMI reflected increased connectivity of visual regions. Together, results demonstrate that network topology of learning and memory regions during choice is related to avoiding a bitter taste, and that BMI is associated with increased connectivity of area involved in processing external stimuli. Network organization and topology provide unique insight into individual differences in brain response to instrumental conditioning via taste reinforcers.
The overconsumption of palatable energy-dense foods drives obesity, but few human studies have in... more The overconsumption of palatable energy-dense foods drives obesity, but few human studies have investigated dopamine (DA) release in response to the consumption of a palatable meal, a putative mediator of excess intake in obesity. We imaged [11C]raclopride in the brain with positron emission tomography (PET) to assess striatal dopamine (DA) receptor binding pre- and post-consumption of a highly palatable milkshake (250 mL, 420 kcal) in 11 females, 6 of whom had severe obesity, and 5 of whom had healthy-weight. Those with severe obesity underwent assessments pre- and 3 months post-vertical sleeve gastrectomy (VSG). Our results demonstrated decreased post- vs. pre-meal DA receptor binding in the ventral striatum (p = 0.032), posterior putamen (p = 0.012), and anterior caudate (p = 0.018), consistent with meal-stimulated DA release. Analysis of each group separately suggested that results in the caudate and putamen were disproportionately driven by meal-associated changes in the health...
Obesity can result from excess intake in response to environmental food cues, and stress can driv... more Obesity can result from excess intake in response to environmental food cues, and stress can drive greater intake and body weight. We used a novel fMRI task to explore how obesity and stress influenced appetitive responses to relatively minimal food cues (words representing food items, presented similarly to a chalkboard menu). Twenty-nine adults (16F, 13M), 17 of whom had obesity and 12 of whom were lean, completed two fMRI scans, one following a combined social and physiological stressor and the other following a control task. A food word reactivity task assessed subjective food approach (wanting) as well as food avoidant (restraint) responses, along with neural responses, to words denoting high energy-density (ED) foods, low-ED foods, and non-foods. A multi-item ad-libitum meal followed each scan. The obese and lean groups demonstrated differences as well as similarities in activation of appetitive and attention/self-regulation systems in response to food vs. non-food, and to hig...
ABSTRACTBackground/Objectives We compared neural organization between individuals with recommende... more ABSTRACTBackground/Objectives We compared neural organization between individuals with recommended, high, and very high body mass indexes (BMI). We hypothesized increased segregation of the putamen and cingulate gyrus with increasing BMI, and an increase in integration of the frontal gyrus in the recommended BMI (BMI < 25) group. Subjects/MethodsThis was a cross-sectional, secondary data analysis of the Human Connectome Project data. Independent components of brain regions (nodal) were used to create correlation matrices for the individuals at a recommended BMI (recBMI; n=156), a high BMI (hBMI; 25 < BMI < 30; n=109), and a very high BMI (vhBMI; BMI > 30; n=78). Graph theory-based metrics were calculated at the nodal, functional network, and module levels and compared between groups. ResultsThe hBMI and vhBMI groups exhibited more modules (9 modules) than the recBMI group (8 modules). The vhBMI showed increased integration in the sensory module and higher connectivity be...
Highly palatable, energy-dense (ED), sweet and savory foods may contribute to the obesity epidemi... more Highly palatable, energy-dense (ED), sweet and savory foods may contribute to the obesity epidemic by triggering desire to eat, experienced by some as an addiction-like response. However, individua...
Background: Weight regain is a concerning issue in bariatric patients. We previously demonstrated... more Background: Weight regain is a concerning issue in bariatric patients. We previously demonstrated that taste-related reward processing was associated with six-month weight loss outcomes following Roux-en-Y gastric bypass (RYGB) but not vertical sleeve gastrectomy (VSG). Here, we assessed whether these taste factors persisted in predicting weight loss, and weight regain, at one year post-surgery. Methods: Adult women enrolled in a longitudinal study of taste preferences following bariatric surgery completed behavioral and neuroimaging assessments at one year post-surgery. Results: RYGB produced better weight loss relative to VSG, with weight regain and greater weight loss variability observed from six months to one year post-VSG. Changes in liking for high fat at 2 weeks post-surgery from baseline remained a predictor of weight loss in RYGB, but other predictors did not persist. Average liking ratings rebounded to baseline and higher self-reported food cravings and dietary disinhibit...
Objectives The 2020 dietary guidelines specifically recommended a decrease in sugar intake. Rewar... more Objectives The 2020 dietary guidelines specifically recommended a decrease in sugar intake. Reward-related, brain-based models of overeating and obesity suggest that increased intake of highly palatable foods is linked to decreased dopaminergic (striatal and prefrontal) brain functioning. This reduction acts to increase consumption of food to achieve pleasure. Here, we examined whether increased dietary intake of sugar and fat would be associated with increased activation in reward-related brain regions during anticipation of a sugar sweetened beverage (SSB), but decreased activation during SSB receipt. Methods Young adults (n = 100, age = 21.8 ± 2.4 y, BMI = 23.3 ± 3.5, 70% female) underwent an fMRI scan examining brain responses to receipt of a SSB, a tasteless rinse, and response cue-induced anticipation of these tastes. The Block Food Frequency Questionnaire (FFQ) was used to assess average dietary intake, % daily caloric intake from SSBs, sugar, sugar from SSBs and fat. These w...
Taste sensitivity and liking drive food choices and ingestive behaviors from childhood to adultho... more Taste sensitivity and liking drive food choices and ingestive behaviors from childhood to adulthood, yet their longitudinal association with dietary intake and BMI is largely understudied. Here, we examined the longitudinal relationship between sugar and fat sensitivity, sugar and fat liking, habitual dietary intake, and BMI percentiles in a sample of 105 healthy-weight adolescents (baseline: BMI %tile 57.0 ± 24.3; age 14–16 years) over a 4-year period. Taste sensitivity was assessed via a triangle fat and sweet taste discrimination test. Taste liking were rated on a visual analog scale for four milkshakes that varied in sugar and fat contents (high-fat/high-sugar (HF/HS), low-fat/high-sugar (LF/HS), high-fat/low-sugar (HF/LS), low-fat/low-sugar (LF/LS) milkshakes). A modified version of the reduced Block Food Frequency Questionnaire (BFFQ) was used to assess dietary intake. All measurements were repeated annually. Repeated measures correlations and linear mixed effects models were ...
Identifying correlates of brain response to food cues and taste provides critical information on ... more Identifying correlates of brain response to food cues and taste provides critical information on individual differences that may influence variability in eating behavior. However, a few studies examine how brain response changes over repeated exposures and the individual factors that are associated with these changes. Using functional magnetic resonance imaging, we examined how brain response to a palatable taste and proceeding cues changed over repeated exposures and how individual differences in weight, familial obesity risk, dietary restraint and reward responsiveness correlate with these changes. In healthy-weight adolescents (n = 154), caudate and posterior cingulate cortex (PCC) response increased with repeated cue presentations, and oral somatosensory cortex and insula response increased with repeated milkshake tastes. The magnitude of increase over exposures in the left PCC to cues was positively associated with body mass index percentile (r = 0.18, P = 0.026) and negatively...
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Papers by Afroditi Papantoni