Supplemental Digital Content is available in the text. Two recent studies challenged traditional paradigms of mammalian sodium physiology, suggesting that sodium reduction might cause weight gain by altering metabolism. This new theory has important implications for population-wide dietary recommendations. However, these observations have not been confirmed. In the DASH (Dietary Approaches to Stop Hypertension)-Sodium trial, 412 adults with systolic blood pressure of 120 to 159 mm Hg and diastolic blood pressure of 80 to 95 mm Hg not taking antihypertensive medications were randomly assigned to the DASH diet or a control diet (parallel design). On their assigned diet, participants randomly consumed each of the 3 sodium levels for 4 weeks (crossover design). Participants were provided all meals but could drink noncaloric beverages (eg, water) freely. Throughout the trial, energy intake was adjusted to maintain weight constant. The 3 sodium levels (at 2100 kcal/day) were: low (1150 mg of Na/day), medium (2300 mg of Na/day), and high (3450 mg of Na/day). Energy intake, weight, self-reported thirst, and 24-hour urine volume were assessed after each period. Participants were 57% women and 57% black; mean age was 48 years [SD, 10]). Among those assigned the control, mean weight increased slightly with higher sodium but not among those assigned DASH. Energy intake did not vary across sodium levels in either diet (P-trends ≥0.36). Higher sodium resulted in more thirst (P-trends <0.001 on both diets) and higher urine volume (suggesting higher fluid intake) during the control diet (P-trend=0.007). Reducing sodium did not increase energy requirements to maintain stable weights but did decrease thirst and urine volume (control diet only), findings consistent with the traditional understanding of mammalian sodium physiology. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000608.

中文翻译：

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减钠对能量、代谢、体重、口渴和尿量的影响

补充数字内容在文本中可用。最近的两项研究挑战了哺乳动物钠生理学的传统范式，表明钠的减少可能通过改变新陈代谢而导致体重增加。这一新理论对全人群的饮食建议具有重要意义。但是，这些观察结果尚未得到证实。在 DASH（停止高血压的饮食方法）-钠试验中，412 名收缩压为 120 至 159 mmHg 且舒张压为 80 至 95 mmHg 且未服用抗高血压药物的成年人被随机分配到 DASH 饮食组或对照组饮食（平行设计）。在他们指定的饮食中，参与者随机消耗 3 种钠水平中的每一种，持续 4 周（交叉设计）。参与者提供所有膳食，但可以喝无热量饮料（例如，水）自由。在整个试验过程中，调整能量摄入以保持体重恒定。3 种钠水平（2100 kcal/天）是：低（1150 mg Na/天）、中（2300 mg Na/天）和高（3450 mg Na/天）。在每个时期后评估能量摄入、体重、自我报告的口渴和 24 小时尿量。参与者是 57% 的女性和 57% 的黑人；平均年龄为 48 岁 [SD, 10]）。在分配给对照组的人中，平均体重随着钠含量的增加而略有增加，但在分配给 DASH 的人中没有。两种饮食中钠水平的能量摄入没有变化（P趋势≥0.36）。在对照饮食期间，较高的钠导致更多的口渴（两种饮食的 P 趋势 <0.001）和较高的尿量（表明较高的液体摄入量）（P 趋势 = 0.007）。减少钠含量不会增加维持体重稳定所需的能量，但确实会减少口渴和尿量（仅控制饮食），这一发现与哺乳动物钠生理学的传统理解一致。临床试验注册网址：http://www.clinicaltrials.gov。唯一标识符：NCT00000608。