Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa-city, Saitama, 359-1192, Japan.
National Institute of Health and Nutrition, National Institutes of Biomedical Innovation, Health and Nutrition, 17-34 Senrioka-Shimmachi, Settsu-city, Osaka, 566-0002, Japan.
Nutr J. 2023 Nov 29;22(1):64. doi: 10.1186/s12937-023-00896-z.
Although water is essential to the maintenance of health and life, standard values for human water requirements are yet to be determined. This study aimed to evaluate the distribution of water turnover (WT) according to sex and age, estimated using a prediction equation, in Japanese adolescents and adults.
This cross-sectional study used data from the 2016 National Health and Nutrition Survey, Japan. Data were obtained from electronically available aggregated reports in the survey's official website. Participants aged between 15 and 80 years (10,546 men, 12,355 women) were selected using stratified random sampling. WT was calculated considering lifestyle and environmental factors, and using an equation (coefficient of determination = 0.471) previously developed by the international doubly labelled water (DLW) database group. As data on physical activity levels (PAL) were not collected in the survey, we used two evaluation methods: (1) energy intake assessed by dietary records and (2) total energy expenditure measured by the DLW method reported in previous Japanese studies, divided by basal metabolic rate predicted using the equation. We evaluated the relationship between WT and age using a restricted cubic spline model.
The average WT for the 15-19, 20-29, 30-39, 40-49, 50-59, 60-69, and ≥ 70 years was 3291, 3151, 3213, 3243, 3205, 3104, and 2790 ml/day, respectively in men, and 2641, 2594, 2741, 2739, 2753, 2707, and 2482 ml/day, respectively in women. In the spline model, WT showed an inverse association with age in men older than 50 years, whereas women showed a reverse U-shaped relationship between WT and age (p for non-linearity < 0.001), although results differed with body weight adjustment. Similar results were found for both PAL evaluation methods, and the range of WT per body weight was 45-56 ml/day for both sexes.
We determined the standard values of WT in Japanese population using a prediction equation and national large-scale survey data. These findings may be useful for setting water requirements for dietary guidelines in future.
尽管水是维持健康和生命所必需的，但人类的需水量标准尚未确定。本研究旨在评估根据性别和年龄分布的水周转量（WT），并使用预测方程进行估计，该方程适用于日本青少年和成年人。
本横断面研究使用了 2016 年日本全国健康和营养调查的数据。数据来自调查官方网站上可电子获取的汇总报告。使用分层随机抽样选择了年龄在 15 至 80 岁之间的参与者（男性 10546 人，女性 12355 人）。考虑到生活方式和环境因素，使用国际双标记水（DLW）数据库组先前开发的方程（决定系数=0.471）计算 WT。由于调查中未收集体力活动水平（PAL）的数据，我们使用了两种评估方法：（1）通过膳食记录评估的能量摄入，（2）使用以前日本研究中报告的 DLW 方法测量的总能量消耗除以使用方程预测的基础代谢率。我们使用受限立方样条模型评估 WT 与年龄之间的关系。
男性 15-19、20-29、30-39、40-49、50-59、60-69 和≥70 岁的平均 WT 分别为 3291、3151、3213、3243、3205、3104 和 2790ml/天，女性分别为 2641、2594、2741、2739、2753、2707 和 2482ml/天。在样条模型中，WT 与年龄呈负相关，年龄大于 50 岁的男性，而女性的 WT 与年龄呈反 U 型关系（非线性检验 p<0.001），尽管结果因体重调整而异。两种 PAL 评估方法均得出了相似的结果，男女的 WT 体重比为 45-56ml/天。
我们使用预测方程和全国大规模调查数据确定了日本人群的 WT 标准值。这些发现可能有助于为未来的膳食指南设定水需求。
