Division of Endocrinology, Metabolism, and Diabetes, University of Colorado, School of Medicine, Aurora, CO, USA.
Int J Obes (Lond). 2013 Sep;37(9):1192-7. doi: 10.1038/ijo.2012.202. Epub 2012 Dec 11.
The roles that energy expenditure (EE) and nutrient oxidation play in a predisposition for weight gain in humans remains unclear.
We measured EE and respiratory exchange ratio (RER) in non-obese obesity-prone (OP; n=22) and obesity-resistant (OR; n=30) men and women following a eucaloric (EU) diet and after 3 days of overfeeding (1.4 × basal energy).
Twenty-four hour EE, adjusted for fat-free mass and sex, measured while consuming a EU diet was not different between OP and OR subjects (2367±80 vs 2285±98 kcals; P=0.53). Following overfeeding, EE increased in both OP and OR (OP: 2506±63.7, P<0.01; OR: 2386±99 kcals, P<0.05). Overfeeding resulted in an increase in 24-hour RER (OP: 0.857±0.01 to 0.893±0.01, P=0.01; OR: 0.852±0.01 to 0.886±0.01, P=0.005), with no difference between groups in either the EU or overfeeding conditions (P>0.05). Nighttime RER (∼10pm-6:30am) did not change with overfeeding in OR (0.823±0.02 vs 0.837±0.01, P=0.29), but increased significantly in OP subjects (0.798±0.15 to 0.839±0.15, P<0.05), suggesting that fat oxidation during the night was downregulated to a greater extent in OP subjects following a brief period of overfeeding, as compared with OR subjects who appeared to maintain their usual rate of fat oxidation. Protein oxidation increased significantly in both OP (P<0.001) and OR (P<0.01) with overfeeding, with no differences between OP and OR.
These results support the idea that overfeeding a mixed diet results in increases in EE and RER, but these increases in EE and RER are likely not responsible for obesity resistance. Adaptive responses to overfeeding that occur during the night may have a role in opposing weight gain.
能量消耗（EE）和营养氧化在人类易发生体重增加中的作用仍不清楚。
我们在非肥胖肥胖易感（OP；n=22）和肥胖抵抗（OR；n=30）男性和女性中测量了 EE 和呼吸交换率（RER），在接受热量平衡（EU）饮食后和 3 天的过食（基础能量的 1.4 倍）后。
在摄入 EU 饮食时，OP 和 OR 受试者的 24 小时 EE（按去脂体重和性别调整）没有差异（2367±80 与 2285±98 千卡；P=0.53）。过食后，OP 和 OR 的 EE 均增加（OP：2506±63.7，P<0.01；OR：2386±99 千卡，P<0.05）。过食导致 24 小时 RER 增加（OP：0.857±0.01 至 0.893±0.01，P=0.01；OR：0.852±0.01 至 0.886±0.01，P=0.005），两组在 EU 或过食条件下均无差异（P>0.05）。OR 夜间 RER（约晚上 10 点至早上 6 点 30 分）在过食期间没有变化（0.823±0.02 与 0.837±0.01，P=0.29），但 OP 受试者明显增加（0.798±0.15 至 0.839±0.15，P<0.05），表明与 OR 受试者相比，OP 受试者在短时间的过食后，夜间脂肪氧化明显下调，而 OR 受试者似乎保持了其通常的脂肪氧化率。OP（P<0.001）和 OR（P<0.01）的蛋白质氧化均随过食显著增加，OP 和 OR 之间无差异。
这些结果支持这样的观点，即混合饮食的过食会导致 EE 和 RER 的增加，但这些 EE 和 RER 的增加可能不是肥胖抵抗的原因。过食期间夜间发生的适应性反应可能在对抗体重增加方面发挥作用。
