Unit of Clinical and Health Psychology, University of Fribourg, Fribourg, Switzerland.
Department of Consultation-Liaison-Psychiatry and Psychosomatic Medicine, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
PLoS One. 2020 May 19;15(5):e0232813. doi: 10.1371/journal.pone.0232813. eCollection 2020.
Worldwide, nearly 3 million people die every year because of being overweight or obese. Although obesity is a metabolic disease, behavioral aspects are important in its etiology. Hunger changes the rewarding potential of food in normal-weight controls. In obesity, impairments related to reward processing are present, but it is not clear whether these are due to mental disorders more common among this population. Therefore, in this pilot study, we aimed at investigating whether fasting influence mood reactivity to reward in people with obesity. Women with obesity (n = 11, all mentally healthy) and normal weight controls (n = 17) were compared on a computerized monetary reward task (the wheel of fortune), using self-reports of mood and affect (e.g., PANAS and mood evaluation during the task) as dependent variables. This task was done in 2 satiety conditions, during fasting and after eating. Partially, in line with our expectation of a reduced affect and mood reactivity to monetary reward in participants with obesity accentuated by fasting, our results indicated a significant within-group difference across time (before and after the task), with monetary gains significantly improving positive affect in healthy controls (p>0.001), but not in individuals with obesity (p = 0.32). There were no significant between-group differences in positive affect before (p = 0.328) and after (p = 0.70) the task. In addition, women with obesity, compared to controls, reported more negative affect in general (p < 0.05) and less mood reactivity during the task in response to risky gains (p < 0.001) than healthy controls. The latter was independent of the level of satiety. These preliminary results suggest an impairment in mood reactivity to monetary reward in women with obesity which is not connected to the fasting state. Increasing the reinforcing potential of rewards other than food in obesity may be one target of intervention in order to verify if that could reduce overeating.
全球每年有近 300 万人因超重或肥胖而死亡。尽管肥胖是一种代谢性疾病，但行为因素在其发病机制中很重要。饥饿改变了正常体重人群对食物的奖赏潜能。在肥胖中，与奖赏处理相关的损伤是存在的，但尚不清楚这些损伤是否是由于该人群中更为常见的精神障碍所致。因此，在这项初步研究中，我们旨在研究禁食是否会影响肥胖人群对奖赏的情绪反应。我们比较了 11 名肥胖女性（均无精神障碍）和 17 名正常体重对照者在计算机化货币奖赏任务（幸运轮）中的表现，使用情绪和情感的自我报告（如 PANAS 和任务期间的情绪评估）作为因变量。该任务在禁食和进食后两种饱腹状态下进行。部分符合我们的预期，即禁食会加重肥胖参与者的情感和情绪对金钱奖赏的反应性，我们的结果表明，时间上存在显著的组内差异（任务前后），金钱收益显著改善了健康对照组的积极情绪（p>0.001），但对肥胖个体没有影响（p = 0.32）。任务前后，健康对照组之间的积极情绪没有显著的组间差异（p = 0.328 和 p = 0.70）。此外，与对照组相比，肥胖女性普遍报告更多的消极情绪（p < 0.05），且对风险收益的任务期间的情绪反应性较低（p < 0.001）。后者与饱腹感水平无关。这些初步结果表明，肥胖女性对金钱奖赏的情绪反应性受损，与禁食状态无关。增加肥胖人群除食物以外的奖励的强化潜力可能是干预的一个目标，以验证这是否可以减少暴饮暴食。
