Abstract：
Restricted sugar and ketogenic diets can alter energy balance/metabolism, but decreased energy intake may be compensated by reduced expenditure. In healthy adults, randomization to restricting free sugars or overall carbohydrates (ketogenic diet) for 12 weeks reduces fat mass without changing energy expenditure versus control. Free-sugar restriction minimally affects metabolism or gut microbiome but decreases low-density lipoprotein cholesterol (LDL-C). In contrast, a ketogenic diet decreases glucose tolerance, increases skeletal muscle PDK4, and reduces AMPK and GLUT4 levels. By week 4, the ketogenic diet reduces fasting glucose and increases apolipoprotein B, C-reactive protein, and postprandial glycerol concentrations. However, despite sustained ketosis, these effects are no longer apparent by week 12, when gut microbial beta diversity is altered, possibly reflective of longer-term adjustments to the ketogenic diet and/or energy balance. These data demonstrate that restricting free sugars or overall carbohydrates reduces energy intake without altering physical activity, but with divergent effects on glucose tolerance, lipoprotein profiles, and gut microbiome.
摘要：
限制糖和生酮饮食可以改变能量平衡/新陈代谢，但是能量摄入的减少可以通过减少支出来补偿。在健康的成年人中，与对照组相比,随机限制游离糖或总碳水化合物(生酮饮食)12周可减少脂肪量,而不会改变能量消耗.游离糖限制对代谢或肠道微生物组的影响最小，但会降低低密度脂蛋白胆固醇（LDL-C）。相比之下,生酮饮食会降低葡萄糖耐量，增加骨骼肌PDK4，并降低AMPK和GLUT4水平。到第4周，生酮饮食会降低空腹血糖并增加载脂蛋白B，C反应蛋白,和餐后甘油浓度。然而,尽管有持续的酮症,到第12周，当肠道微生物β多样性改变时，这些影响不再明显，可能反映了生酮饮食和/或能量平衡的长期调整。这些数据表明，限制游离糖或整体碳水化合物会减少能量摄入，而不会改变身体活动。但是对葡萄糖耐量有不同的影响，脂蛋白概况，和肠道微生物组。
