The School of Allied Health and Community, 8709University of Worcester, Worcester, UK.
Nutr Health. 2022 Dec;28(4):543-554. doi: 10.1177/02601060221083079. Epub 2022 Mar 7.
Low-carbohydrate diets may have endocrine effects, although individual studies are conflicting. Therefore, a review was conducted on the effects of low- versus high-carbohydrate diets on men's testosterone and cortisol. The review was registered on PROSPERO (CRD42021255957). The inclusion criteria were: intervention study, healthy adult males, and low-carbohydrate diet: ≤35% carbohydrate. Eight databases were searched from conception to May 2021. Cochrane's risk of bias tool was used for quality assessment. Random-effects, meta-analyses using standardized mean differences and 95% confidence intervals, were performed with Review Manager. Subgroup analyses were conducted for diet duration, protein intake, and exercise duration. Twenty-seven studies were included, with a total of 309 participants. Short-term (<3 weeks), low- versus high-carbohydrate diets moderately increased resting cortisol (0.41 [0.16, 0.66], < 0.01). Whereas, long-term (≥3 weeks), low-carbohydrate diets had no consistent effect on resting cortisol. Low- versus high-carbohydrate diets resulted in much higher post-exercise cortisol, after long-duration exercise (≥20 min): 0 h (0.78 [0.47, 1.1], < 0.01), 1 h (0.81 [0.31, 1.31], < 0.01), and 2 h (0.82 [0.33, 1.3], < 0.01). Moderate-protein (<35%), low-carbohydrate diets had no consistent effect on resting total testosterone, however high-protein (≥35%), low-carbohydrate diets greatly decreased resting (-1.08 [-1.67, -0.48], < 0.01) and post-exercise total testosterone (-1.01 [-2, -0.01] = 0.05). Resting and post-exercise cortisol increase during the first 3 weeks of a low-carbohydrate diet. Afterwards, resting cortisol appears to return to baseline, whilst post-exercise cortisol remains elevated. High-protein diets cause a large decrease in resting total testosterone (∼5.23 nmol/L).
低碳水化合物饮食可能会对内分泌产生影响，尽管个别研究存在矛盾。因此，对低碳水化合物与高碳水化合物饮食对男性睾酮和皮质醇的影响进行了综述。该综述已在 PROSPERO（CRD42021255957）上注册。纳入标准为：干预研究、健康成年男性、低碳水化合物饮食：碳水化合物≤35%。从构思到 2021 年 5 月，检索了 8 个数据库。使用 Cochrane 偏倚风险工具进行质量评估。使用 Review Manager 进行随机效应、使用标准化均数差和 95%置信区间的荟萃分析。进行了饮食持续时间、蛋白质摄入量和运动持续时间的亚组分析。纳入了 27 项研究，共 309 名参与者。短期（<3 周）低碳水化合物与高碳水化合物饮食适度增加了静息皮质醇（0.41 [0.16, 0.66]，<0.01）。然而，长期（≥3 周）低碳水化合物饮食对静息皮质醇没有一致的影响。在长时间（≥20 分钟）运动后，低碳水化合物与高碳水化合物饮食导致更高的运动后皮质醇：0 小时（0.78 [0.47, 1.1]，<0.01），1 小时（0.81 [0.31, 1.31]，<0.01），和 2 小时（0.82 [0.33, 1.3]，<0.01）。中等蛋白（<35%）低碳水化合物饮食对静息总睾酮没有一致的影响，然而高蛋白（≥35%）低碳水化合物饮食大大降低了静息（-1.08 [-1.67, -0.48]，<0.01）和运动后总睾酮（-1.01 [-2, -0.01] = 0.05）。低碳水化合物饮食的前 3 周会导致静息皮质醇增加。之后，静息皮质醇似乎恢复到基线，而运动后皮质醇仍然升高。高蛋白饮食会导致静息总睾酮大量下降（约 5.23 nmol/L）。
