Buemann B, Toubro S, Astrup A
Research Department of Human Nutrition, The Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
Int J Obes Relat Metab Disord. 1998 Sep;22(9):869-77. doi: 10.1038/sj.ijo.0800674.
To investigate the adaptation in substrate utilization to a sudden change in dietary composition from a medium fat to a high fat diet, during a three day period in formerly obese and never obese women.
Energy expenditure (EE) and substrate oxidation rates were measured in eight healthy formerly obese women and eight never obese controls, during four consecutive days in a respiration chamber. The first day and the day prior to the experiment, the subjects consumed a diet with 30 energy-% fat, whereas the diet had 55 energy-% fat on the subsequent three days.
The rate of adjustment of oxidative substrate partitioning expressed as 24 h non-protein respiratory quotient (RQnp) was similar in the two groups. RQnp on each of the days was also similar between the two groups, after accounting for a group difference in energy balance, caused by a non-significantly lower EE in the formerly obese women. However, the formerly obese subjects, demonstrated a greater suppression of postprandial fat oxidation after supper, which was unrelated to energy balance. Furthermore, the formerly obese subjects, in contrast to the controls, exhibited a reduction in plasma triiodothyronine/thyroxine ratio (T3/T4) following the high fat diet. A positive correlation between T3/T4 and EE was found in the 16 subjects.
The formerly obese subjects did not show a slower adaptation rate of substrate utilization when challenged with a high fat diet, but exhibited an enhanced suppression of fat oxidation and a lower T3/T4 ratio after supper, when fed a high fat diet.
研究既往肥胖和从未肥胖的女性在三天时间内，饮食组成从中等脂肪饮食突然转变为高脂肪饮食时，机体对底物利用的适应性变化。
在呼吸室内，对8名健康的既往肥胖女性和8名从未肥胖的对照者连续四天测量能量消耗（EE）和底物氧化率。实验前一天和第一天，受试者食用脂肪供能占30%的饮食，随后三天食用脂肪供能占55%的饮食。
以24小时非蛋白呼吸商（RQnp）表示的氧化底物分配调整率在两组中相似。在考虑到既往肥胖女性的EE略低（无统计学意义）所导致的能量平衡组间差异后，两组中每天的RQnp也相似。然而，既往肥胖的受试者在晚餐后餐后脂肪氧化的抑制作用更强，这与能量平衡无关。此外，与对照组相比，既往肥胖的受试者在食用高脂肪饮食后血浆三碘甲状腺原氨酸/甲状腺素比值（T3/T4）降低。在这16名受试者中发现T3/T4与EE呈正相关。
既往肥胖的受试者在接受高脂肪饮食挑战时，底物利用的适应速度并未减慢，但在食用高脂肪饮食后，晚餐后脂肪氧化的抑制作用增强，T3/T4比值降低。
