Relation of reward from food intake and anticipated food intake to obesity: A functional magnetic resonance imaging study.

Abstract

We tested the hypothesis that obese individuals experience greater reward from food consumption (consummatory food reward) and anticipated consumption (anticipatory food reward) than lean individuals using functional magnetic resonance imaging (fMRI) with 33 adolescent girls (M age = 15.7 SD = 0.9). Obese relative to lean adolescent girls showed greater activation bilaterally in the gustatory cortex (anterior and mid insula, frontal operculum) and in somatosensory regions (parietal operculum and Rolandic operculum) in response to anticipated intake of chocolate milkshake (versus a tasteless solution) and to actual consumption of milkshake (versus a tasteless solution); these brain regions encode the sensory and hedonic aspects of food. However, obese relative to lean adolescent girls also showed decreased activation in the caudate nucleus in response to consumption of milkshake versus a tasteless solution, potentially because they have reduced dopamine receptor availability. Results suggest that individuals who show greater activation in the gustatory cortex and somatosensory regions in response to anticipation and consumption of food, but who show weaker activation in the striatum during food intake, may be at risk for overeating and consequent weight gain. Keywordsobesity; anticipatory food reward; consummatory food reward; fMRI Obesity is a chronic disease that is credited with over 111,000 deaths annually in the US, which largely result from atherosclerotic cerebrovascular disease, coronary heart disease, colorectal cancer, hyperlipidemia, hypertension, gallbladder disease, and diabetes mellitus (Flegal, Graubard, Williamson, & Gail, 2005). Regrettably, the treatment of choice for obesity only results in transitory weight loss (Jeffery et al., 2000) and most obesity prevention programs do not reduce risk for future weight gain (Stice, Shaw, & Marti, 2006). These interventions may have limited efficacy because our understanding of the etiologic processes is still incomplete. Although it has been established that obesity is the result of a positive energy balance, it is Correspondence should be addressed to Eric Stice, who is at Oregon Research Institute, 1715 Franklin Blvd., Eugene, Oregon, 97403. Email: E-mail: estice@ori.org. 3 Based on the evidence that reward-related neural function in women is heightened during the mid-follicular phase (Dreher et al., 2007), we created a dichotomous variable that reflected whether participants completed the fMRI scans during the midfollicular phase (days 4-8 after onset of menses; n = 2) or not (n = 31). When we controlled for this variable in all analyses, the activation in the reported regions remained significant. One possible explanation is that some individuals have abnormalities in subjective reward from food intake or anticipated intake that increase risk for obesity. Some scholars hypothesize that obese individuals experience greater activation of the meso-limbic reward system in response to food intake (consummatory food reward), which may increase risk ...

Exercise and Weight Loss: What Is the Evidence of Sex Differences?

“…Several studies have evaluated neuronal responses to visual food cues at rest, showing changes in brain regions essential to the regulation of energy intake [48][49][50][51][52][53][54][55][56]. Killgore et al [51] observed significant activity in numerous food reward, inhibitory control, and visual brain regions (e.g., insula, amygdala, medial frontal gyrus, precuneus, etc.)…”

Reward activity in satiated overweight women is decreased during unbiased viewing but increased when imagining taste: an event-related fMRI study

“…[14][15][16] Previous neuroimaging research in obese versus healthy-weight participants showed increased activity in several of these brain reward regions while viewing high-calorie versus neutral or low-calorie food pictures in a hungry state, 17 in a non-hungry state, 18,19 and in response to anticipated or actual consumption of a chocolate milkshake in a hungry state. 20 Most of these studies involved 'unbiased viewing', meaning that food pictures are shown without the instruction to imagine their taste.…”

Altered reward anticipation: Potential explanation for weight gain in schizophrenia?

“…A reduction in striatal dopamine-2 receptors was found in pathologically obese participants (Wang et al, 2001). This led to the hypothesis that obesity shares some neurobiological mechanisms with addiction disorders, for example, and mainly, the need to compensate for a decreased sensitivity of dopamine D2-regulated reward circuits by impulsive eating (Stice et al, 2008a(Stice et al, , 2008bWang et al, 2004). While this provides us with good evidence that the dopaminergic reward system is involved, it gives us no information about reward anticipation in MID paradigms.…”

“…In overweight adolescents, Stice and colleagues observed overactivation in the striatum as well as in OFC, insula, and opercular regions during anticipation of a food reward (Stice et al, 2008a(Stice et al, , 2008b. This altered response in individuals who were at risk for obesity was identified as an imaging biomarker for obesity risk.…”

“…Second, in MID paradigms − presumably reflecting phasic dopaminergic responses − reward anticipation differs in obese or binge-eating patients on the one hand and healthy non-obese controls on the other (Balodis et al, 2013;Stice et al, 2008aStice et al, , 2008bStoeckel et al, 2008). However, an apparent conundrum is the direction in which the striatal fMRI signal changes.…”