EXERCISE AND DIET EFFECTS ON LACTATION PERFORMANCE

许多美国女性希望在产后减肥 经常通过限制卡路里摄入或锻炼来帮助实现这一点 进球。然而，目前还不清楚能量平衡可以被改变到什么程度。 在哺乳受到影响之前。拟议研究的目标是 评估短期卡路里限制或锻炼的效果 热量限制对哺乳性能的影响。专属的女性 产后8-12周的母乳喂养将随机分配给3人中的一人 组(N=25个/组)，为期11天：A)对照组，给予100%能量 需要；b)将卡路里限制在65%的能量需要；和c)运动加 限制卡路里，造成与b组类似的卡路里不足。 对基线能量摄入和消耗的测量将用于 确定最初的能量需求，并将作为饮食的基础 在干预期间提供和规定的锻炼水平。数据在 乳量和乳汁成分、血浆催乳素、母体成分 和婴儿体重将在11-d之前和期间收集。 干预期。奶量将通过三维测试称量来确定。 使用电子天平。牛奶样本将由另一人采集 乳房表情超过24小时，并分析脂肪、乳糖、蛋白质、能量 和脂肪酸浓度。将测定血浆催乳素水平 留置尿管采集血样的放射免疫分析 在母乳喂养之前、期间和之后。母体 成分将通过流体静压称量和重氢进行评估。 在呼吸水中稀释。重复测量方差分析意志 被用来检查干预的影响。这样做的结果 研究将有助于确定安全的最低卡路里摄入量 美国妇女的哺乳期。

Many women in the U.S. desire to lose weight during the postpartum period and often turn to caloric restriction or exercise to help accomplish this goal. However, it is unknown to what extent energy balance can be altered before lactation is compromised. The goal of the proposed research is to evaluate the effect of short-term caloric restriction or exercise with caloric restriction on lactation performance. Women who are exclusively breastfeeding at 8-12 wk postpartum will be randomly assigned to one of 3 groups (N=25/group) for a period of 11 d: a) control, given 100% of energy needs; b) caloric restriction to 65% of energy needs; and c) exercise plus caloric restriction to create a similar caloric deficit as in group b. Measurements of baseline energy intake and expenditure will be used to determine initial energy needs and will serve as the basis for the diets furnished and exercise levels prescribed during the intervention. Data on milk volume and composition, plasma prolactin, maternal body composition and infant weight will be collected prior to and during the 11-d intervention period. Milk volume will be determined by 3-d test-weighing using an electronic balance. Milk samples will be collected by alternate breast expression over 24 h and analyzed for fat, lactose, protein, energy and fatty acid concentrations. Plasma prolactin levels will be determined by radioimmunoassay from blood samples collected by indwelling catheter before, during and after a breastfeeding episode. Maternal body composition will be assessed by hydrostatic weighing and deuterium dilution in respiratory water. Repeated measures analysis of variance will be used to examine the impact of the intervention. The results of this study will be useful for determining a safe minimal caloric intake during lactation for U.S. women.