Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL.
Division of Gerontology, Geriatrics, and Palliative Care, University of Alabama at Birmingham, Birmingham, AL.
J Nutr. 2018 Feb 1;148(2):220-226. doi: 10.1093/jn/nxx040.
The ability to oxidize fat is associated with a lower risk of chronic metabolic disease. Preclinical data in mice showed that a high-fat "breakfast" increased 24-h fat oxidation relative to a high-carbohydrate breakfast.
The objectives of this study were to determine whether the timing of macronutrient intake in humans affects daily fuel utilization and to examine associations between fuel utilization and metabolic indexes.
Participants were 29 healthy sedentary men and women (aged 55-75 y) with a body mass index (kg/m2) between 25 and 35. Participants were randomly assigned to receive either a high-fat breakfast (FB; 35% carbohydrate, 20% protein, 45% fat; n = 13) or a high-carbohydrate breakfast (CB; 60% carbohydrate, 20% protein, 20% fat; n = 16) for 4 wk while consuming a "neutral" lunch and dinner. Twenty-four-hour and postprandial respiratory quotients (RQs) were measured by whole-room indirect calorimetry. Insulin and glucose measures including insulin sensitivity were determined by an oral-glucose-tolerance test. Measures were taken at baseline and after the 4-wk intervention. Group-by-time interactions were determined by 2-factor repeated-measures mixed-model ANOVA. Pearson's correlation analyses were used to determine associations of 24-h RQs with metabolic measures after the intervention.
There was a significant group-by-time interaction for change in the 24-h RQ [FB (mean ± SD): 0.88 ± 0.02 to 0.86 ± 0.02; CB: 0.88 ± 0.02 for both; P < 0.05], breakfast RQ (FB: 0.88 ± 0.03 to 0.86 ± 0.03; CB: 0.89 ± 0.02 to 0.90 ± 0.02; P < 0.01), and lunch RQ (FB: 0.089 ± 0.03 to 0.85 ± 0.03; CB: 0.89 ± 0.03 for both; P < 0.01). In the CB group at follow-up, 24-h RQ was positively associated with fasting glucose (r = 0.66, P < 0.05), glucose area under the curve (AUC) (r = 0.51, P < 0.05), and insulin AUC (r = 0.52, P < 0.05) and inversely associated with insulin sensitivity (r = -0.51, P < 0.05).
The macronutrient composition of breakfast affects substrate utilization throughout the day in older adults. The consumption of a high-fat, lower-carbohydrate breakfast may reduce the risk of metabolic disease. This trial was registered at www.clinicaltrials.gov as NCT03164200.
氧化脂肪的能力与慢性代谢性疾病的风险较低有关。在小鼠的临床前数据中，高脂肪的“早餐”比高碳水化合物早餐增加了 24 小时脂肪氧化。
本研究的目的是确定人类摄入宏量营养素的时间是否会影响日常燃料利用，并检查燃料利用与代谢指标之间的关联。
参与者为 29 名健康的久坐男性和女性（年龄 55-75 岁），体重指数（kg/m2）在 25-35 之间。参与者被随机分配接受高脂肪早餐（FB；35%碳水化合物，20%蛋白质，45%脂肪；n=13）或高碳水化合物早餐（CB；60%碳水化合物，20%蛋白质，20%脂肪；n=16），持续 4 周，同时摄入“中性”午餐和晚餐。通过整个房间间接测热法测量 24 小时和餐后呼吸商（RQ）。通过口服葡萄糖耐量试验确定胰岛素和葡萄糖测量值，包括胰岛素敏感性。在基线和 4 周干预后进行测量。通过 2 因素重复测量混合模型方差分析确定组间时间交互作用。Pearson 相关分析用于确定干预后 24 小时 RQ 与代谢测量值之间的关联。
24 小时 RQ 的组间时间交互作用有显著差异[FB（均值±SD）：0.88±0.02 至 0.86±0.02；CB：0.88±0.02 均为；P<0.05]，早餐 RQ（FB：0.88±0.03 至 0.86±0.03；CB：0.89±0.02 均为；P<0.01）和午餐 RQ（FB：0.089±0.03 至 0.85±0.03；CB：0.89±0.03 均为；P<0.01）。在 CB 组随访时，24 小时 RQ 与空腹血糖（r=0.66，P<0.05）、血糖曲线下面积（AUC）（r=0.51，P<0.05）和胰岛素 AUC（r=0.52，P<0.05）呈正相关，与胰岛素敏感性（r=-0.51，P<0.05）呈负相关。
早餐的宏量营养素组成会影响老年人全天的底物利用。食用高脂肪、低碳水化合物的早餐可能会降低患代谢性疾病的风险。本试验在 www.clinicaltrials.gov 上注册为 NCT03164200。
