Weight Loss May Improve Decision-Making and Mood in Severely Obese People: Study

A recent Clinical Nutrition study examined how significant weight loss in highly obese individuals influences their metabolism, psychological state, and decision-making processes.

Research shows that metabolic signals, like blood glucose levels, have been essential for survival, influencing decisions on territory and mating by indicating energy needs. Glucose helps the brain gauge if more resources are required, and mood also affects decision-making.

Emotional eating, aimed at improving mood, often leads to high-calorie food overconsumption and increased obesity risk. Obesity disrupts metabolism and raises blood glucose levels. However, there is limited research on how restoring glucose function and mood might affect decision-making.

The study explored how metabolic and psychological factors affect risky decision-making in obese individuals and examined the impact of weight loss on these decisions. Participants engaged in a computerized gambling task to assess risk propensity, with HbA1c levels and mood measured using the PANAS questionnaire. It was hypothesized that risk-taking would be positively correlated with BMI and that HbA1c would become a stronger predictor of risk propensity after weight loss.

62 obese participants completed a ten-day medically supervised weight loss program, including nutrition counseling and psychotherapy. They made choices between risky options with uncertain rewards and safe options with guaranteed, intermediate rewards. Blood samples, body fat, and weight measurements were recorded at the start and end of the program.

The results showed that weight loss significantly improved both HbA1c levels and mood, making HbA1c a reliable predictor of risk propensity post-weight loss and leading to mood enhancements. HbA1c levels negatively predicted risky decisions, with higher levels associated with lower risk-taking, likely due to perceived high energy availability and a strategy to minimize risk.

Participants were more likely to choose risky options before weight loss, whereas post-intervention, they exhibited reduced risk propensity—a positive behavioural change linked to a healthier lifestyle. Additionally, dopaminergic signalling may influence the relationship between BMI and risk propensity, with lower glucose levels associated with a preference for immediate, smaller rewards over larger, delayed ones.

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 indicated that physiological variables like mood could be targeted to prevent individuals from engaging in maladaptive behaviours that lead to weight gain.

Reference: Keweloh, B., Terenzi, D., Froehlich, E., et al. (2024) Weight loss impacts risky decisions in obesity. Clinical Nutrition 43; 1270-1277. doi:10.1016/j.clnu.2024.04.002, https://www.clinicalnutritionjournal.com/article/S0261-5614(24)00108-0/fulltext