Mota João F, Gonzalez Maria Cristina, Lukaski Henry, Oto Gabriela L, Trottier Claire F, Tibaes Jenneffer R B, Prado Carla M
Department of Agricultural, Food and Nutritional Science, University of Alberta, Li Ka Shing Centre for Health Research Innovation, Edmonton, AB, T6G 2E1, Canada.
Clinical and Sports Nutrition Research Laboratory (LABINCE), Faculty of Nutrition, Federal University of Goiás, Goiânia, GO, 74.605-080, Brazil.
Eur J Clin Nutr. 2022 Feb;76(2):212-219. doi: 10.1038/s41430-021-00932-3. Epub 2021 May 13.
Bioelectrical impedance analysis (BIA) is a widely used method for estimating body composition. Avoiding foods/beverages containing caffeine is a frequently enforced pre-test protocol to ensure reliability of BIA measurements. However, few studies have evaluated whether this is necessary, with conflicting results. We aimed to determine whether the coffee consumption differing in caffeine content influences BIA parameters in healthy adults.
Twenty-five healthy adults were enrolled in a randomized, double-blind cross-over trial. Three amounts of caffeine were given with 200 mL of coffee: 0 mg (11 g of decaffeinated), 200 mg (5.5 g of caffeinated plus 5.5 g of decaffeinated), and 400 mg of caffeine (11 g of caffeinated). BIA measurements were conducted at 6 different times, and coefficient variations (CV) explored.
No differences were observed for group × time interaction on impedance, resistance, or reactance (p > 0.05). Values of BIA parameters increased after 30-min of coffee consumption, independently of the caffeine dosage (all p < 0.001). Body fat percentage followed the same pattern and increased after 45-min (p < 0.05). Median CV for consecutive impedance, resistance, and reactance measurements were >95%CI of expected device measurement error over 70-min, without difference between groups. Urine output volume was not different between groups (decaffeinated: 440.45 ± 197.57 mL; 200 mg: 471.80 ± 171.88 mL; 400 mg: 489.30 ± 204.10 mL, p > 0.05).
Coffee consumption influenced BIA-derived results after 70-min but was not related to caffeine content, likely due to water intake.
生物电阻抗分析（BIA）是一种广泛用于评估身体成分的方法。避免食用/饮用含咖啡因的食物/饮料是一项经常执行的测试前方案，以确保BIA测量的可靠性。然而，很少有研究评估这是否必要，结果相互矛盾。我们旨在确定不同咖啡因含量的咖啡摄入量是否会影响健康成年人的BIA参数。
25名健康成年人参加了一项随机、双盲交叉试验。将三种咖啡因剂量与200毫升咖啡一起给予：0毫克（11克脱咖啡因咖啡）、200毫克（5.5克含咖啡因咖啡加5.5克脱咖啡因咖啡）和400毫克咖啡因（11克含咖啡因咖啡）。在6个不同时间进行BIA测量，并探讨变异系数（CV）。
在阻抗、电阻或电抗方面，未观察到组×时间交互作用的差异（p>0.05）。饮用咖啡30分钟后，BIA参数值增加，与咖啡因剂量无关（所有p<0.001）。体脂百分比遵循相同模式，在45分钟后增加（p<0.05）。连续阻抗、电阻和电抗测量的中位数CV在70分钟内>预期设备测量误差的95%置信区间，组间无差异。各组间尿量无差异（脱咖啡因组：440.45±197.57毫升；200毫克组：471.80±171.88毫升；400毫克组：489.30±204.10毫升，p>0.05）。
饮用咖啡70分钟后会影响BIA得出的结果，但与咖啡因含量无关，可能是由于水分摄入。
