Is it Worth the Effort? Novel Insights into Obesity-Associated Alterations in Cost-Benefit Decision-Making

Abstract

Cost-benefit decision-making entails the process of evaluating potential actions according to the trade-off between the expected reward (benefit) and the anticipated effort (costs). Recent research revealed that dopaminergic transmission within the fronto-striatal circuitry strongly modulates cost-benefit decision-making. Alterations within the dopaminergic fronto-striatal system have been associated with obesity, but little is known about cost-benefit decision-making differences in obese compared with lean individuals. With a newly developed experimental task we investigate obesity-associated alterations in cost-benefit decision-making, utilizing physical effort by handgrip-force exertion and both food and non-food rewards. We relate our behavioral findings to alterations in local gray matter volume assessed by structural MRI. Obese compared with lean subjects were less willing to engage in physical effort in particular for high-caloric sweet snack food. Further, self-reported body dissatisfaction negatively correlated with the willingness to invest effort for sweet snacks in obese men. On a structural level, obesity was associated with reductions in gray matter volume in bilateral prefrontal cortex. Nucleus accumbens volume positively correlated with task induced implicit food craving. Our results challenge the common notion that obese individuals are willing to work harder to obtain high-caloric food and emphasize the need for further exploration of the underlying neural mechanisms regarding cost-benefit decision-making differences in obesity.

Neural correlates of effort-based valuation with prospective choices

“…In contrast to ACC, premotor areas and insular cortex that encode arousal or salience (Bartra et al 2013;Rangel and Clithero 2013). Similar to other studies of effort-based decisions (Burke, Brunger, et al 2013;Mathar et al 2016), our design included an effort task where the participants did not reach the target goal in all of the effort trials. We accounted for this uncertainty component (probability of not making the goal) in our model, yet we acknowledge that future designs should separate between these components.…”

Associations between Obesity and Spinal Diseases: A Medical Expenditure Panel Study Analysis

“…Although we are unable to tell the exact causal mechanism behind these associational patterns given the cross-sectional nature of our data, our finding that obesity predicts spinal diseases in the lower back but not in the cervical region provides more support for the mechanical-structural hypothesis than for metabolic or behavioral hypothesis. From a policy and management viewpoint, if the causal link between spinal disease and obesity is further substantiated by longitudinal and interventional studies, the health care expenditure associated with obesity might be even higher than the current estimates [83,84,85,86] and thus the cost-benefit ratio of obesity interventions might be more favorable that what has been estimated so far [87,88,89,90,91]. In other words, further research is needed where researchers employ longitudinal analyses or interventional studies examining whether weight loss leads to improvement of spinal conditions.…”

Studies using pharmacological blockade of muscle afferents provide new insights into the neurophysiology of perceived exertion

“…A newly published study suggests that obese people, compared with lean people, may be characterized by an abnormal cost–benefit decision‐making that undervalues the reward obtained from the engagement in physical exercise (Mathar et al . ). Unexpectedly, Mathar et al .…”

“…Unexpectedly, Mathar et al . () demonstrated that obese individuals, compared with lean individuals, are less willing to engage in physical effort to obtain high caloric sweet snack food rewards.…”

“…the process of choosing between different options) relies on a cost-benefit comparison from which the option that entails the best trade-off is chosen over the others. A newly published study suggests that obese people, compared with lean people, may be characterized by an abnormal cost-benefit decision-making that undervalues the reward obtained from the engagement in physical exercise (Mathar et al 2016). Unexpectedly, Mathar et al (2016) demonstrated that obese individuals, compared with lean individuals, are less willing to engage in physical effort to obtain high caloric sweet snack food rewards.…”