Dufour D L, Reina J C, Spurr G
Department of Anthropology, University of Colorado, Boulder, 80309-0233, USA.
Am J Clin Nutr. 1999 Aug;70(2):269-76. doi: 10.1093/ajcn.70.2.269.
This study examined the components of energy balance in poor, free-living pregnant women living in an urban setting of a developing country.
We tested the following hypotheses: 1) energy intake increases in pregnancy and is greater than when nonpregnant and nonlactating (NPNL), 2) basal metabolic rate (BMR) increases in pregnancy and the increase is positively correlated with prepregnancy fatness, and 3) energy expenditure in activity decreases in pregnancy and is lower than in NPNL women.
Pregnant women were studied at 14.8 +/- 3.4 (n = 40), 25.0 +/- 3.2 (n = 54), and 34.9 +/- 2.4 (n = 43) wk gestation, and NPNL women at baseline (n = 114) and at 3 (n = 103) and 6 (n = 93) mo. Energy intake was measured by using estimated diet records and energy expenditure by using the flex heart rate method. Time allocation in physical activity was assessed by observation.
In pregnant women, body weight, BMR, and energy intake increased but total daily energy expenditure (TDEE) did not change significantly. There were no significant changes in time allocation to selected activities except for lying down. In comparison with NPNL control subjects, women in late pregnancy had higher energy intakes and BMRs. Values for TDEE were not significantly different, but pregnant women expended less energy in activity and allocated more time to 2 energy-saving activities and less time to 2 energy-demanding activities.
A decrease in energy expenditure in activity and changes in time allocation are important ways in which pregnant women meet the energy demands of pregnancy.
本研究调查了生活在发展中国家城市地区贫困的非住院孕妇的能量平衡组成部分。
我们检验了以下假设:1)孕期能量摄入增加,且高于非孕期和非哺乳期(NPNL)时的能量摄入;2)孕期基础代谢率(BMR)增加,且这种增加与孕前肥胖程度呈正相关;3)孕期活动中的能量消耗减少,且低于NPNL女性。
对孕期14.8±3.4周(n = 40)、25.0±3.2周(n = 54)和34.9±2.4周(n = 43)的孕妇进行研究,同时对NPNL女性在基线(n = 114)、3个月(n = 103)和6个月(n = 93)时进行研究。通过估计饮食记录测量能量摄入,使用灵活心率法测量能量消耗。通过观察评估身体活动中的时间分配。
孕妇的体重、BMR和能量摄入增加,但每日总能量消耗(TDEE)没有显著变化。除了躺下之外,选定活动的时间分配没有显著变化。与NPNL对照对象相比,孕晚期女性的能量摄入量和BMR更高。TDEE值没有显著差异,但孕妇在活动中消耗的能量较少,且将更多时间分配给两项节能活动,将较少时间分配给两项耗能活动。
活动中能量消耗的减少和时间分配的变化是孕妇满足孕期能量需求的重要方式。