Human Nutrition Research Unit, Department of Agricultural, Food, & Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada.
Am J Clin Nutr. 2021 Feb 2;113(2):476-487. doi: 10.1093/ajcn/nqaa283.
High-protein diets and total diet replacements are becoming increasingly popular for weight loss; however, further research is needed to elucidate their impact on the mechanisms involved in weight regulation.
The aim of this inpatient metabolic balance study was to compare the impact of a high-protein total diet replacement (HP-TDR) versus a control diet (CON) on select components of energy metabolism in healthy adults of both sexes.
The acute intervention was a randomized, controlled, crossover design with participants allocated to 2 isocaloric arms: 1) HP-TDR: 35% carbohydrate, 40% protein, and 25% fat achieved through a nutritional supplement; 2) CON: 55% carbohydrate, 15% protein, and 30% fat. Participants received the prescribed diets for 32 h while inside a whole-body calorimetry unit (WBCU). The first dietary intervention randomly offered in the WBCU was designed to maintain energy balance and the second matched what was offered during the first stay. Energy expenditure, macronutrient oxidation rates and balances, and metabolic blood markers were assessed. Body composition was measured at baseline using DXA.
Forty-three healthy, normal-weight adults (19 females and 24 males) were included. Compared with the CON diet, the HP-TDR produced higher total energy expenditure [(EE) 81 ± 82 kcal/d, P <0.001], protein and fat oxidation rates (38 ± 34 g/d, P <0.001; 8 ± 20 g/d, P = 0.013, respectively), and a lower carbohydrate oxidation rate (-38 ± 43 g/d, P <0.001). Moreover, a HP-TDR led to decreased energy (-112 ± 85 kcal/d; P <0.001), fat (-22 ± 20 g/d; P <0.001), and carbohydrate balances (-69 ± 44 g/d; P <0.001), and increased protein balance (90 ± 32 g/d; P <0.001).
Our primary findings were that a HP-TDR led to higher total EE, increased fat oxidation, and negative fat balance. These results suggest that a HP-TDR may promote fat loss compared with a conventional isocaloric diet. These trials were registered at clinicaltrials.gov as NCT02811276 and NCT03565510.
高蛋白饮食和全饮食替代物在减肥方面越来越受欢迎；然而，需要进一步的研究来阐明它们对参与体重调节的机制的影响。
本住院代谢平衡研究的目的是比较高蛋白全饮食替代物（HP-TDR）与对照饮食（CON）对健康成年男女的能量代谢选择成分的影响。
急性干预采用随机、对照、交叉设计，参与者分为 2 个等热量组：1）HP-TDR：通过营养补充剂实现 35%碳水化合物、40%蛋白质和 25%脂肪；2）CON：55%碳水化合物、15%蛋白质和 30%脂肪。参与者在全身热量计单元（WBCU）内接受规定的饮食 32 小时。WBCU 中提供的第一种饮食干预旨在维持能量平衡，第二种饮食与第一次入住时提供的饮食相匹配。评估能量消耗、宏量营养素氧化率和平衡以及代谢血液标志物。基线时使用 DXA 测量身体成分。
共纳入 43 名健康、体重正常的成年人（19 名女性和 24 名男性）。与 CON 饮食相比，HP-TDR 产生更高的总能量消耗[（EE）81±82kcal/d，P<0.001]、蛋白质和脂肪氧化率（38±34g/d，P<0.001；8±20g/d，P=0.013），以及较低的碳水化合物氧化率（-38±43g/d，P<0.001）。此外，HP-TDR 导致能量减少（-112±85kcal/d；P<0.001）、脂肪减少（-22±20g/d；P<0.001）和碳水化合物平衡减少（-69±44g/d；P<0.001），并增加蛋白质平衡（90±32g/d；P<0.001）。
我们的主要发现是，HP-TDR 导致总 EE 增加、脂肪氧化增加和脂肪负平衡。这些结果表明，与传统等热量饮食相比，HP-TDR 可能促进脂肪流失。这些试验在 clinicaltrials.gov 上注册为 NCT02811276 和 NCT03565510。
