Xu Ting, Liu Jing-Jing, Liu Zi-Qi, Qi Xu-Ge, Zhang Hong-Wei, Liu Lin, Ban Xu-Yan, Li Qing, Han Xiao-Dong, Zheng Hui, Huang Xin-Yu, Di Jian-Zhong
1Department of Metabolic & Bariatric Surgery, Shanghai Jiao Tong University School of Medicine Affiliated Sixth People's Hospital, Shanghai, 200233, China.
2Department of Psychosomatic Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200120, China.
J Behav Addict. 2025 Jan 22;14(1):522-533. doi: 10.1556/2006.2024.00073. Print 2025 Mar 28.
Food addiction and an impulsive personality can increase overeating, which can lead to weight gain. The amygdala and nucleus accumbens (NAcc) are critical for regulating obesogenic behaviour. However, whether the amygdala or the NAcc acts as the neural basis for the regulation of food addiction, impulsive personality, and body weight remains unclear.
We examined the differences in the volume of the amygdala and NAcc, especially the lateralization index (LI), between 33 obese participants and 39 age- and sex-matched healthy controls. The associations of the LI of each brain region with clinical variables and body mass index (BMI) were identified using network analysis. Finally, we explored the relationships among the LIs of brain regions, impulsive personality, food addiction, and BMI through a multiple chain mediation model.
We observed a significant decrease in the LI of the amygdala in the obese group compared with the healthy group (F = 20.276, p < 0.001), which indicates that the right amygdala was larger than the left amygdala in the obese group. Network analysis revealed that the LI of the amygdala was very closely associated with nonplanning impulsivity, food addiction and BMI. The results of the mediation analysis indicated that increased nonplanning impulsiveness could lead to weight gain through increased food addiction (β = 0.069, SE = 0.043, 95% CI [0.014, 0.184]). Moreover, in this symptom chain, the LI of the amygdala can mediate the relationship between food addiction and BMI (β = 0.018, SE = 0.014, 95% CI [0.002, 0.061]).
Our observations indicate a substantial reduction in the LI of the amygdala among individuals with obesity, suggesting a structural predisposition. The findings reveal a potential neural mechanism that can help explain the interplay between impulsivity, food addiction, and obesity.
食物成瘾和冲动型人格会增加暴饮暴食，进而导致体重增加。杏仁核和伏隔核（NAcc）对调节致肥胖行为至关重要。然而，杏仁核或伏隔核是否作为调节食物成瘾、冲动型人格和体重的神经基础仍不清楚。
我们检查了33名肥胖参与者与39名年龄和性别匹配的健康对照者之间杏仁核和伏隔核的体积差异，特别是偏侧化指数（LI）。使用网络分析确定每个脑区的LI与临床变量和体重指数（BMI）之间的关联。最后，我们通过多重链式中介模型探索脑区LI、冲动型人格、食物成瘾和BMI之间的关系。
我们观察到肥胖组杏仁核的LI与健康组相比显著降低（F = 20.276，p < 0.001），这表明肥胖组右侧杏仁核大于左侧杏仁核。网络分析显示杏仁核的LI与非计划性冲动、食物成瘾和BMI密切相关。中介分析结果表明，非计划性冲动增加可通过食物成瘾增加导致体重增加（β = 0.069，SE = 0.043，95% CI [0.014, 0.184]）。此外，在这个症状链中，杏仁核的LI可介导食物成瘾与BMI之间的关系（β = 0.018，SE = 0.014，95% CI [0.002, 0.061]）。
我们的观察结果表明肥胖个体杏仁核的LI大幅降低，提示存在结构易感性。研究结果揭示了一种潜在的神经机制，有助于解释冲动性、食物成瘾和肥胖之间的相互作用。
