Individuals with severe obesity experience not only altered risk behaviours but also significant changes in their metabolism and psychological state. Historically, it was believed that individuals with severe obesity are more impulsive and have a greater inclination towards risk-taking. Researchers from the DZD partner, the German Institute of Human Nutrition Potsdam-Rehbrücke (DIfE), have delved into whether substantial weight loss can lessen these metabolic and psychological disturbances and enhance decision-making abilities. Their comprehensive study and findings have been documented in the journal Clinical Nutrition.
Many factors influence behaviour, including personality and internal physiological signals such as glucose metabolism and emotional state. Studies indicate that in obese individuals, these internal signals are disrupted; impaired glucose metabolism and mood disturbances fail to provide reliable bases for decision-making. In an attempt to investigate whether these conditions are reversible, Beatrix Keweloh, a doctoral candidate in the Department of Neuroscience of Decision and Nutrition, and her team initiated an intervention study. They recruited 62 participants with severe obesity, ranging in age from 18 to 75 years, and subjected them to a rigorous 10-week diet that restricted their daily caloric intake to 800 kilocalories. The study meticulously measured participants’ weight, body fat, mood through questionnaires, and risk-taking tendencies via a computer-based test before and after the diet regimen.
The intervention led to significant health improvements, as evidenced by substantial reductions in body mass index (BMI) and HbA1c levels, the latter serving as a critical marker for glucose metabolism. Alongside these metabolic enhancements, there was a marked improvement in participants’ moods. The study intriguingly revealed a shift towards more risk-averse behaviour, underscoring a strong correlation between BMI and risk behaviour in obesity. Beatrix Keweloh noted, “Our findings underscore that post-weight loss, the metabolic factor HbA1c becomes the dominant predictor of risk-taking behaviours.”
The study’s implications are profound, indicating that mood exerts less influence over decision-making after weight loss, with metabolic signals taking precedence. This shift suggests that weight loss improves physical health parameters and restores the functional integrity of glucose metabolism as a critical decision-making signal. Beatrix Keweloh summarised the outcomes, highlighting the dual benefits of weight loss on glucose metabolism and mood, ultimately restoring the reliability of physiological signals in supporting decision-making processes.
More information: Beatrix Keweloh et al, Weight loss impacts risky decisions in obesity, Clinical Nutrition. DOI: 10.1016/j.clnu.2024.04.002
Journal information: Clinical Nutrition Provided by Deutsches Zentrum für Diabetesforschung DZD
