Grandjean A C, Reimers K J, Bannick K E, Haven M C
The Center for Human Nutrition, Omaha 68105, USA.
J Am Coll Nutr. 2000 Oct;19(5):591-600. doi: 10.1080/07315724.2000.10718956.
To examine the effect of various combinations of beverages on hydration status in healthy free-living adult males.
In a counterbalanced, crossover manner, 18 healthy adult males ages 24 to 39, on four separate occasions, consumed water or water plus varying combinations of beverages. Clinical guidelines were used to determine the fluid allowance for each subject. The beverages were carbonated, caffeinated caloric and non-caloric colas and coffee. Ten of the 18 subjects consumed water and carbonated, non-caffeinated, citrus soft drink during a fifth trial. Body weight, urine and blood assays were measured before and after each treatment.
Slight body weight loss was observed on all treatments, with an average of 0.30% for all treatments. No differences (p>0.05) among treatments were found for body weight changes or any of the biochemical assays. Biochemical assays conducted on first voids and 24-hour urines included electrolytes, creatine, osmolality and specific gravity. Blood samples were analyzed for hemoglobin, hematocrit. electrolytes, osmolality, urea nitrogen, creatinine and protein.
This preliminary study found no significant differences in the effect of various combinations of beverages on hydration status of healthy adult males. Advising people to disregard caffeinated beverages as part of the daily fluid intake is not substantiated by the results of this study. The across-treatment weight loss observed, when combined with data on fluid-disease relationships, suggests that optimal fluid intake may be higher than common recommendations. Further research is needed to confirm these results and to explore optimal fluid intake for healthy individuals.
研究不同饮料组合对健康自由生活成年男性水合状态的影响。
18名年龄在24至39岁的健康成年男性以平衡交叉的方式，在四个不同场合分别饮用了水或水加不同组合的饮料。采用临床指南确定每位受试者的液体摄入量。这些饮料包括碳酸饮料、含咖啡因的有热量和无热量可乐及咖啡。18名受试者中的10人在第五次试验中饮用了水和碳酸、不含咖啡因的柑橘味软饮料。在每次治疗前后测量体重、尿液和血液指标。
所有治疗均观察到轻微体重减轻，所有治疗的平均体重减轻为0.30%。在体重变化或任何生化指标方面，各治疗组之间未发现差异（p>0.05）。对首次排尿和24小时尿液进行的生化检测包括电解质、肌酸、渗透压和比重。对血液样本分析了血红蛋白、血细胞比容、电解质、渗透压、尿素氮、肌酐和蛋白质。
这项初步研究发现，不同饮料组合对健康成年男性水合状态的影响无显著差异。本研究结果未证实建议人们将含咖啡因饮料排除在日常液体摄入量之外的说法。观察到的各治疗组体重减轻，结合液体与疾病关系的数据，表明最佳液体摄入量可能高于常见建议。需要进一步研究来证实这些结果，并探索健康个体的最佳液体摄入量。
