O'Neal Eric K, Smith Ashton F, Heatherly Alexander J, Killen Lauren G, Waldman Hunter S, Hollingsworth Angela, Koh Yunsuk
University of North Alabama, Florence, AL, USA.
Middle Tennessee State University, Murfreesboro, TN, USA.
Int J Exerc Sci. 2019 May 1;12(2):786-799. doi: 10.70252/VMVW2171. eCollection 2019.
This study examined glucose and lipid marker responses following a 3-week, ad libitum low-carbohydrate-high-fat diet (LCHF; ~70% kcals from fat, <50 g/day of net carbohydrates) versus the habitual mixed macronutrient diet (HMD) of eight middle-age, trained male runners (40 ± 10 years; V̇Opeak = 49 ± 4 mL·kg·min). Blood was drawn at 0600 from an antecubital vein after an overnight fast under conditions of no exercise/heat stress (NEXH; 48 h of restriction from intense exercise) or 24-h after exercise/heat stress (EXH; 60 min run in hot conditions plus 5-km time trial) for both dietary conditions. Glucose improvement during LCHF approached but did not reach statistical significance (p = 0.07). Pre-exercise triacylglycerol did not differ between treatments but decreased > 20 mg/dL (p < 0.05) for both treatments from NEXH to EXH (HMD = 42 ± 16; LCHF = 35 ± 21 mg/dL). Main effects for diet were exhibited for HDL-C during NEXH and EXH (HMD = 48 ± 10 and 50 ± 11; LCHF = 57 ± 13 and 60 ± 13 mg/dL), and LDL-C also increased (p = 0.02) by ~20 mg/dL for LCHF at both collection points resulting in ~30 mg/dL greater total cholesterol for LCHF before and 24-h after exercise (p < 0.05). A 3-week, ad libitum LCHF did not elicit significant negative cardiovascular disease risk in male runners 30-50 years of age with healthy pre-intervention lipid and glucose marker status.
本研究对8名中年训练有素的男性跑步者（40±10岁；峰值摄氧量=49±4 mL·kg·min）进行了为期3周的随意低碳水化合物高脂肪饮食（LCHF；约70%的热量来自脂肪，每日净碳水化合物<50克）与习惯性混合宏量营养素饮食（HMD）的对比，观察其葡萄糖和脂质标志物的反应。在无运动/热应激（NEXH；限制剧烈运动48小时）或运动/热应激后24小时（EXH；在炎热条件下跑步60分钟加5公里计时赛）的两种饮食条件下，于上午06:00从肘前静脉采血。LCHF期间葡萄糖改善接近但未达到统计学显著性（p = 0.07）。运动前甘油三酯在两种治疗之间无差异，但两种治疗从NEXH到EXH均下降>20 mg/dL（p < 0.05）（HMD = 42±16；LCHF = 35±21 mg/dL）。在NEXH和EXH期间，饮食对HDL-C有主要影响（HMD = 48±10和50±11；LCHF = 57±13和60±13 mg/dL），LCHF在两个采集点的LDL-C也增加了约20 mg/dL（p = 0.02），导致运动前和运动后24小时LCHF的总胆固醇比HMD高约30 mg/dL（p < 0.05）。对于干预前脂质和葡萄糖标志物状态健康的30 - 50岁男性跑步者，为期3周的随意LCHF并未引发显著的负面心血管疾病风险。
