Gower Barbara A, Goss Amy M
Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL
Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL.
J Nutr. 2015 Jan;145(1):177S-83S. doi: 10.3945/jn.114.195065. Epub 2014 Dec 3.
Obesity, particularly visceral and ectopic adiposity, increases the risk of type 2 diabetes.
The aim of this study was to determine if restriction of dietary carbohydrate is beneficial for body composition and metabolic health.
Two studies were conducted. In the first, 69 overweight/obese men and women, 53% of whom were European American (EA) and 47% of whom were African American (AA), were provided with 1 of 2 diets (lower-fat diet: 55%, 18%, and 27% of energy from carbohydrate, protein, and fat, respectively; lower-carbohydrate diet: 43%, 18%, and 39%, respectively) for 8 wk at a eucaloric level and 8 wk at a hypocaloric level. In the second study, 30 women with polycystic ovary syndrome (PCOS) were provided with 2 diets (lower-fat diet: 55%, 18%, and 27% of energy from carbohydrate, protein, and fat, respectively; lower-carbohydrate diet: 41%, 19%, and 40%, respectively) at a eucaloric level for 8 wk in a random-order crossover design.
As previously reported, among overweight/obese adults, after the eucaloric phase, participants who consumed the lower-carbohydrate vs. the lower-fat diet lost more intra-abdominal adipose tissue (IAAT) (11 ± 3% vs. 1 ± 3%; P < 0.05). After weight loss, participants who consumed the lower-carbohydrate diet had 4.4% less total fat mass. Original to this report, across the entire 16-wk study, AAs lost more fat mass with a lower-carbohydrate diet (6.2 vs. 2.9 kg; P < 0.01), whereas EAs showed no difference between diets. As previously reported, among women with PCOS, the lower-carbohydrate arm showed decreased fasting insulin (-2.8 μIU/mL; P < 0.001) and fasting glucose (-4.7 mg/dL; P < 0.01) and increased insulin sensitivity (1.06 arbitrary units; P < 0.05) and "dynamic" β-cell response (96.1 · 10(9); P < 0.001). In the lower-carbohydrate arm, women lost both IAAT (-4.8 cm(2); P < 0.01) and intermuscular fat (-1.2 cm(2); P < 0.01). In the lower-fat arm, women lost lean mass (-0.6 kg; P < 0.05). Original to this report, after the lower-carbohydrate arm, the change in IAAT was positively associated with the change in tumor necrosis factor α (P < 0.05).
A modest reduction in dietary carbohydrate has beneficial effects on body composition, fat distribution, and glucose metabolism. This trial was registered at clinicaltrials.gov as NCT00726908 and NCT01028989.
肥胖，尤其是内脏脂肪和异位脂肪增多，会增加患2型糖尿病的风险。
本研究旨在确定限制膳食碳水化合物是否对身体成分和代谢健康有益。
进行了两项研究。第一项研究中，69名超重/肥胖的男性和女性（其中53%为欧美裔美国人[EA]，47%为非裔美国人[AA]）被给予两种饮食中的一种（低脂饮食：碳水化合物、蛋白质和脂肪提供的能量分别占55%、18%和27%；低碳水化合物饮食：分别占43%、18%和39%），在等热量水平下持续8周，然后在低热量水平下持续8周。在第二项研究中，30名患有多囊卵巢综合征（PCOS）的女性采用随机交叉设计，在等热量水平下被给予两种饮食（低脂饮食：碳水化合物、蛋白质和脂肪提供的能量分别占55%、18%和27%；低碳水化合物饮食：分别占41%、19%和40%），持续8周。
如先前报道，在超重/肥胖成年人中，等热量阶段后，食用低碳水化合物饮食的参与者比食用低脂饮食的参与者减少了更多的腹部内脏脂肪组织（IAAT）（分别为11±3%和1±3%；P<0.05）。体重减轻后，食用低碳水化合物饮食的参与者总脂肪量减少了4.4%。本报告首次发现，在整个16周的研究中，非裔美国人食用低碳水化合物饮食时脂肪量减少更多（6.2对2.9千克；P<0.01），而欧美裔美国人在两种饮食之间没有差异。如先前报道，在患有多囊卵巢综合征的女性中，低碳水化合物组的空腹胰岛素水平降低（-2.8 μIU/mL；P<０.００１），空腹血糖降低（-4.7 mg/dL；P<0.01），胰岛素敏感性增加（1.06个任意单位；P<0.05），“动态”β细胞反应增强（96.1·10(9)；P<0.001）。在低碳水化合物组中，女性的腹部内脏脂肪组织（-4.8 cm(2)；P<0.01）和肌间脂肪（-1.2 cm(2)；P<0.01）均减少。在低脂组中，女性的瘦体重减少（-0.6千克；P<0.05）。本报告首次发现，低碳水化合物组后，腹部内脏脂肪组织的变化与肿瘤坏死因子α的变化呈正相关（P<0.05）。
适度减少膳食碳水化合物对身体成分、脂肪分布和葡萄糖代谢具有有益影响。本试验在clinicaltrials.gov上注册，注册号为NCT00726908和NCT01028989。
