Institute of Human Nutrition and Food Science, Christian-Albrechts University, Kiel, Germany.
Eur J Clin Nutr. 2013 Sep;67(9):984-9. doi: 10.1038/ejcn.2013.131. Epub 2013 Jul 17.
BACKGROUND/OBJECTIVES: Adiposity rebound (AR) is defined as the nadir or the inflexion point of body mass index (BMI) percentiles between the age of 3 and 7 years. An early rebound is seen as a risk of obesity and, thus, AR is considered as a suitable time period for prevention. As BMI does not reflect body composition, we aimed to examine the rebounds of fat mass index (FMI) and fat-free mass index (FFMI) together with BMI.
SUBJECTS/METHODS: Cross-sectional data of 19 264 children aged 3-11 years were pooled from three German studies (Kiel Obesity Prevention Study, the project 'Better diet. More exercise. KINDERLEICHT-REGIONS' and regular examinations of Jena children). Height and weight were measured. Fat mass (FM) and fat-free mass (FFM) were obtained from bioelectrical impedance analysis and analysed using a population-specific algorithm. Percentiles of BMI, FMI and FFMI were constructed by the LMS method.
Both BMI and FMI percentiles showed a rebound, whereas FFMI percentiles steadily increased with age. On P90, FMI rebound was about 1.6-1.8 years later compared with that of BMI, that is, at ages 4.2 years (BMI) and 5.8 years (FMI) in boys and at 4.2 years (BMI) and 6.0 years (FMI) in girls. At AR, the slope of the BMI-P90 was explained by increases in FFMI rather than FMI. By contrast, at FMI rebound, the slope of BMI was strongly related to FMI.
BMI rebound does not equal the rebound of FM. At AR, the slope in BMI is determined by the increase in FFMI. AR should be defined as FMI rebound rather than BMI rebound.
背景/目的：体脂量反弹（AR）定义为 3 至 7 岁之间体重指数（BMI）百分位的最低点或拐点。早期反弹被视为肥胖的风险因素，因此 AR 被认为是预防的合适时期。由于 BMI 不能反映身体成分，我们旨在同时检查脂肪量指数（FMI）和去脂体重指数（FFMI）与 BMI 的反弹情况。
受试者/方法：对来自三个德国研究（基尔肥胖预防研究、“更好的饮食。更多的运动。KINDERLEICHT-REGIONS 项目”和耶拿儿童定期检查）的 19264 名 3 至 11 岁儿童的横断面数据进行了汇总。测量了身高和体重。使用生物电阻抗分析法获得了脂肪量（FM）和去脂量（FFM），并使用特定人群的算法进行了分析。BMI、FMI 和 FFMI 的百分位数通过 LMS 方法构建。
BMI 和 FMI 百分位数均出现反弹，而 FFMI 百分位数则随年龄稳步增加。在 P90 时，FMI 反弹比 BMI 晚 1.6-1.8 年，即男孩为 4.2 岁（BMI）和 5.8 岁（FMI），女孩为 4.2 岁（BMI）和 6.0 岁（FMI）。在 AR 时，BMI-P90 的斜率由 FFMI 的增加而不是 FMI 的增加来解释。相比之下，在 FMI 反弹时，BMI 的斜率与 FMI 密切相关。
BMI 反弹不等于 FM 的反弹。在 AR 时，BMI 的斜率由 FFMI 的增加决定。AR 应定义为 FMI 反弹，而不是 BMI 反弹。
