Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institute of Health, 2412 N. 16th St, Phoenix, AZ 85016, USA; Phoenix VA Health Care System, Department of Medicine, Division of Endocrinology, 650 E. Indian School Rd, Phoenix, AZ 85012, USA.
Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institute of Health, 2412 N. 16th St, Phoenix, AZ 85016, USA.
Metabolism. 2019 May;94:59-68. doi: 10.1016/j.metabol.2019.01.016. Epub 2019 Jan 31.
In homeothermic animals, approximately 50% of daily energy expenditure (EE) is spent to maintain a consistent core body temperature (CBT). In humans, little is known about CBT responses to feeding and overfeeding and their relationship to diet-related changes in EE.
To study the effects of feeding and overfeeding on CBT and its association with diet-induced thermogenesis (DIT).
Fifty-three healthy men with normal glucose regulation and a wide range of body composition (mean ± SD, body fat: 25 ± 8%, range: 7-43%) had 24-h EE assessed during fasting in a whole-room indirect calorimeter with concomitant CBT measurement by ingestible capsules and 24-h urinary collection for catecholamine measurements. Changes in 24-h EE (DIT) and CBT compared to fasting were assessed during three normal-protein (20%) diets using a cross-over design: one eucaloric diet (EBL, 50% carbohydrate, n = 37) and two overfeeding diets with 200% energy requirements: a high-fat (FNP, 60% fat, n = 25) and a high-carbohydrate (CNP; 75% carbohydrate, n = 24) diet.
The average 24-h CBT (avgCBT) during fasting was 36.81 ± 0.14 °C (inter-individual CV = 0.4%) and positively correlated with 24-h urinary epinephrine (r = 0.61, p < 0.001), but not with body composition measures (p > 0.05). AvgCBT increased during EBL (Δ = 0.06 ± 0.11 °C, p = 0.002), FNP (Δ = 0.13 ± 0.14 °C, p < 0.001), and CNP (Δ = 0.19 ± 0.13 °C, p < 0.001) and associated with increased DIT during EBL (r = 0.43, p = 0.01, β = 31 kcal/day/0.1 °C) and FNP (r = 0.60, p = 0.002, β = 43 kcal/day/0.1 °C), but not CNP (p = 0.47). A ceiling effect for the increase in CBT, but not in DIT, was observed during feeding and, particularly, overfeeding.
CBT increases with feeding and is moderately associated with DIT to a different degree depending on the macronutrient composition of the overfeeding diet. There is a ceiling effect such that individuals with a higher CBT during fasting have limited capacity to increase CBT with feeding. Because of body thermoregulatory mechanisms that maintain a constant CBT, these results indicate that CBT has a limited role in the inter-individual variability in DIT.
在恒温动物中，大约 50%的日常能量消耗 (EE) 用于维持稳定的核心体温 (CBT)。在人类中，人们对进食和过食对 CBT 的影响及其与 EE 相关的饮食变化的关系知之甚少。
研究进食和过食对 CBT 的影响及其与饮食诱导产热 (DIT) 的关系。
53 名血糖调节正常、体成分差异较大（平均 ± SD，体脂：25 ± 8%，范围：7-43%）的健康男性，在整个房间间接热量计中进行 24 小时 EE 评估，同时通过可摄入胶囊进行 CBT 测量和 24 小时尿收集以测量儿茶酚胺。采用交叉设计，使用三种正常蛋白质（20%）饮食评估 24 小时 EE（DIT）和 CBT 与禁食相比的变化：一种热量平衡饮食（EBL，50%碳水化合物，n=37）和两种过食饮食，能量需求分别为 200%：高脂肪（FNP，60%脂肪，n=25）和高碳水化合物（CNP；75%碳水化合物，n=24）饮食。
禁食期间平均 24 小时 CBT（avgCBT）为 36.81 ± 0.14°C（个体间变异系数为 0.4%），与 24 小时尿肾上腺素呈正相关（r=0.61，p<0.001），但与体成分测量无关（p>0.05）。EBL（Δ=0.06 ± 0.11°C，p=0.002）、FNP（Δ=0.13 ± 0.14°C，p<0.001）和 CNP（Δ=0.19 ± 0.13°C，p<0.001）期间 avgCBT 增加，与 EBL（r=0.43，p=0.01，β=31 千卡/天/0.1°C）和 FNP（r=0.60，p=0.002，β=43 千卡/天/0.1°C）期间 DIT 增加相关，但与 CNP 无关（p=0.47）。在进食和特别是过食期间，CBT 的增加存在上限效应，但 DIT 则没有。
CBT 在进食时增加，与 DIT 呈中度相关，其程度取决于过食饮食的宏量营养素组成。CBT 存在上限效应，因此在禁食时 CBT 较高的个体，进食时 CBT 增加的能力有限。由于身体的体温调节机制维持稳定的 CBT，这些结果表明 CBT 在 DIT 的个体间变异性中作用有限。
