Cornier Marc-Andre, McFadden Kristina L, Thomas Elizabeth A, Bechtell Jamie L, Bessesen Daniel H, Tregellas Jason R
Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, Anschutz Medical Campus, University of Colorado School of Medicine , Aurora, CO , USA ; Anschutz Health and Wellness Center, University of Colorado Anschutz Medical Campus , Aurora, CO , USA.
Department of Psychiatry, Anschutz Medical Campus, University of Colorado School of Medicine , Aurora, CO , USA.
Front Behav Neurosci. 2015 Feb 26;9:52. doi: 10.3389/fnbeh.2015.00052. eCollection 2015.
The mechanisms responsible for the propensity to gain weight or remain normal weight are poorly understood. The objective of this study was to study the neuronal response to visual food cues during short-term energy imbalance in healthy adults recruited as obesity-resistant (OR) or obesity-prone (OP) based on self-identification, body mass index, and personal/family weight history. Twenty-five OR and 28 OP subjects were studied in underfed (UF) and overfed (OF) as compared to eucaloric (EU) conditions in a randomized crossover design. Each study phase included a 3-day run-in diet, 1 day of controlled feeding (basal energy needs for EU, 40% above/below basal energy needs for OF/UF), and a test day. On the test day, fMRI was performed in the acute fed stated (30 min after a test meal) while subjects viewed images of foods of high hedonic value and neutral non-food objects. Measures of appetite and hormones were also performed before and every 30 min after the test meal. UF was associated with significantly increased activation of insula, somatosensory cortex, inferior and medial prefrontal cortex (PFC), parahippocampus, precuneus, cingulate, and visual cortex in OR. However, UF had no impact in OP. As a result, UF was associated with significantly greater activation, specifically in the insula, inferior PFC, and somatosensory cortex in OR as compared to OP. While OF was overall associated with reduced activation of inferior visual cortex, no group interaction was observed with OF. In summary, these findings suggest that individuals resistant to weight gain and obesity are more sensitive to short-term energy imbalance, particularly with UF, than those prone to weight gain. The inability to sense or adapt to changes in energy balance may represent an important mechanism contributing to excess energy intake and risk for obesity.
导致体重增加倾向或维持正常体重的机制目前还知之甚少。本研究的目的是，基于自我认定、体重指数以及个人/家族体重史，对招募的健康成年人中抗肥胖（OR）或易肥胖（OP）个体在短期能量失衡期间对视觉食物线索的神经元反应进行研究。采用随机交叉设计，将25名OR和28名OP受试者在饥饿（UF）和过食（OF）状态下与等热量（EU）状态进行比较研究。每个研究阶段包括3天的适应期饮食、1天的控制饮食（EU为基础能量需求，OF/UF为基础能量需求的40%以上/以下）以及1个测试日。在测试日，受试者在急性进食状态（测试餐后30分钟）观看高享乐价值食物和中性非食物物体的图像时进行功能磁共振成像（fMRI）。在测试餐前以及餐后每30分钟还进行食欲和激素测量。在OR个体中，UF与岛叶、体感皮层、前额叶下皮质和内侧前额叶皮质（PFC）、海马旁回、楔前叶、扣带回和视觉皮层的激活显著增加有关。然而，UF对OP个体没有影响。因此，与OP个体相比，UF与OR个体中特别是岛叶、前额叶下皮质和体感皮层的激活显著增加有关。虽然OF总体上与视觉皮层下激活减少有关，但未观察到OF与组间的相互作用。总之，这些发现表明，与易肥胖个体相比，抗体重增加和肥胖的个体对短期能量失衡更敏感，尤其是在UF状态下。无法感知或适应能量平衡的变化可能是导致能量摄入过多和肥胖风险的一个重要机制。
