A recent Clinical Nutrition study examines how significant weight loss in highly obese individuals influences their metabolism, psychological state, and decision-making processes.
Study: Weight loss impacts risky decisions in obesity. Image Credit: Pixel-Shot / Shutterstock.com
The role of mood and glucose on how decisions are made
Research on human evolution has shown that signals for internal energy resources, such as blood glucose levels, have been essential for survival. For example, decisions about fighting for territory and mating have been associated with energy expenditure in the form of metabolic signals. Metabolic signals also guide behaviors to proactively adapt to fluctuating environments, which reduces food insecurities.
Glucose is an effective signal of internal energy resources because it provides calories for cellular functions. Glucose also informs the brain about available energy reserves, enabling the brain to evaluate the necessity of acquiring more energy resources.
In addition to glucose, mood also influences decision-making processes. From an evolutionary perspective, a low mood prevented our ancestors from searching for food in hopeless situations.
Emotional eating, which involves food intake to comfort an individual’s mood, is considered a maladaptive behavior. A low mood often induces emotional eating, which can lead to the overconsumption of high-calorie foods and, as a result, an increased risk of obesity.
Obesity can alter metabolism rates, which increases blood glucose levels. Few studies have evaluated whether recovery of glucose function and mood could affect human decision-making processes.
About the study
The current study determined the differential mechanisms that are involved in risky decision-making processes in obese individuals with higher levels of both metabolic and psychological variables. The effect of weight loss on decision-making was also evaluated.
To assess decision output, researchers subjected obese participants to a computerized gambling task as a measure of risk propensity assessment. Glycated hemoglobin (HbA1c) levels were measured to monitor long-term blood glucose levels. Study participants also completed a positive and negative affect schedule (PANAS) questionnaire to assess their mood.
Considering previous studies indicating higher risk-taking behaviors in obese individuals, the current research assumed risk propensity to be positively correlated with body mass index (BMI). The researchers also hypothesized that metabolic and psychological factors positively guide decision-making processes as a function of weight loss intervention. HbA1c was expected to be a weak predictor of risk decisions before weight loss but a robust predictor after weight loss.
A total of 62 highly obese participants, 41 women and 21 men, were recruited from the Interdisciplinary Center for Obesity Medicine at Schleswige Holstein University Hospital in Kiel, Germany. All study participants began a medically supervised weight loss program for ten days, as well as nutrition counseling and psychotherapy in group sessions. Blood samples, body fat, and body weight measurements were obtained at weeks zero and 10.
Each study participant was asked to select between risky and safe options. The risky options had a 50% probability of gaining a larger or smaller monetary reward, whereas the safe option had a 100% probability of gaining an intermediate reward.
Study findings
Weight loss significantly improved HbA1c levels and mood. Therefore, HbA1c can be considered a predictor in guiding risk propensity after weight loss, leading to mood improvements.
HbA1c negatively predicted participants’ risky decisions before and after weight loss, as risk propensity was lower in individuals with higher HbA1c levels. This could be because the brain perceived high energy availability and followed the strategy of minimizing risky decisions due to caloric abundance.
Before the weight loss intervention, study participants were more willing to select risky options, as opposed to after they had lost weight through the intervention. This is considered a positive behavioral change, as reduced risk propensity has been associated with a healthier lifestyle.
Dopaminergic signaling could regulate the association between BMI and risk propensity. In the current study, reduced glucose levels were associated with a preference for immediate but small rewards over larger rewards.
Conclusions
Risk propensity decreased after weight loss, as demonstrated by individuals who lost weight after participating in a weight management program being more likely to select a safer option than a risky one. These findings indicate that physiological variables like mood could be targeted to prevent individuals from engaging in maladaptive behaviors that lead to weight gain.
The study findings provide valuable insights into variable factors that contribute to risky decisions in obesity. In the future, additional studies are needed to assess the long-term effects of weight regain on decision-making abilities.
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