能量平衡观察法测定南方轻体力活动健康成人总能量消耗量

目的采用能量平衡观察法探究我国南方轻体力活动健康成人的总能量消耗量。方法选择符合能量代谢试验条件的34名南方轻体力活动健康成人为研究对象,为其设计和制备三日循环膳食,用称重法准确获得每日膳食实际摄入量,并用化学分析法测得膳食能量平均摄入量,结合试验期间的体重变化,得到我国南方健康成人总能量消耗量。结果采用称重-化学分析法测得膳食能量平均摄入量为(8424±1616)kJ/d[(2013±386)kcal/d],其中男性(9990±798)kJ/d[(2388±191)kcal/d],女性(7032±384)kJ/d[(1681±92)kcal/d]。16天的试验期间体重平均减轻0.02kg,其中男性体重平均增长0.15kg,女性体重平均减轻0.17kg,根据成人能量平衡原理最后计算得出我国南方健康成人总能量消耗量为(8468±1762)kJ/d[(2024±421)kcal/d],其中男性为(9680±1759)kJ/d[(2314±420)kcal/d],女性为(7391±827)kJ/d[(1767±198)kcal/d]。结论我国南方轻体力劳动健康成年男性总能量消耗量约为9680±1759kJ/d[(2314±420kcal/d)],女性约为7391±827kJ/d[(1767±198kcal/d)],与2000年制定的男、女性能量推荐值2400kcal和2100kcal相比,该研究男性测量值比其RNI值低86kcal,女性测量值比其RNI值低333kcal。     

75名小学生冬季能量消耗情况

目的了解身高、体重中等儿童每日能量总消耗及运动能量消耗水平,以便为小学营养健康教育提供依据.方法采用UX-1型能量检测仪,记录小学二-六年级学生100名每日能量总消耗(TEE)及运动能量消耗(ECPA),连续检测7 d,其中学习日5 d,休息日2 d.对资料齐全、有效的75名小学生数据进行分析.结果男、女生每日TEE分别为(7055.30±1176.84)kJ和(5789.72±683.72)kJ;ECPA分别为(1116.85±375.91)kJ和(858.61±319.64)kJ.每日运动能量消耗占总能量消耗的百分比,男女学生分别为15.8%和14.8%.结论男女学生每日运动能量消耗占总能量消耗的比例较低,学习日和休息日能量消耗差异不明显,说明学生运动不足.     

加速度计对成人日常体力活动测量效度的研究

目的　对加速度计(CSA)测量成年人日常体力活动的效度进行验证并提出根据 CSA数据预测能量消耗的方程。方法　选取 72 名北京市居民,年龄(43.6±4.0)岁,男性 33 名,女性 39名,作为调查对象,佩带7天CSA,在同一期间采用双标水方法(DLW) 测量能量消耗,包括平均每天总能量消耗(TEE)、平均每天体力活动能量消耗(AEE)和体力活动水平(PAL)作为验证标准。结果通过CSA测量的平均每天活动计数(AC)与TEE、AEE和PAL之间均呈显著相关,偏相关系数 r 分别为0.31、0.30、0.26(P<0.05)。逐步多元回归分析表明,影响TEE的因素包括去脂体重或体重指数、AC(R2=0.52~0.70),影响AEE的因素包括AC、性别和去脂体重(R2=0.25~0.32)。结论　CSA能准确测量中国成年人日常体力活动模式,AC可以解释TEE和AEE的变异。     

能量平衡对腹膜透析患者体重的影响

目的 研究持续非卧床腹膜透析(CAPD)患者的能量摄入和消耗,探讨CAPD患者超重和肥胖的可能影响因素.方法 选择2011年5月至12月在北京大学第三医院门诊稳定透析的115例CAPD患者,根据体质量指数(BMI)分为正常组(18.5 kg/m2≤BMI< 24 kg/m2,n=61)和超重/肥胖组(BMI≥24 kg/m2,n =54).收集患者3d饮食记录,计算饮食热量、蛋白质、脂肪和碳水化合物摄入,测定24 h透析液中吸收的葡萄糖量,测定患者静息能量消耗(REE),收集3d活动记录计算总能量消耗(TEE),进行人体成分分析.结果 两组患者在年龄、身高、饮食热量摄入、饮食蛋白质和碳水化合物摄入、肌肉量、水负荷方面的差异无统计学意义.超重/肥胖组患者透析液中吸收的葡萄糖热量和饮食脂肪摄入量均显著高于正常组[(1 920.5 ±506.3) kJ/d比(1 673.6±535.6) kJ/d,x2=2.536,P=0.013; (62.5±19.8) g/d比(53.1 ±18.7) g/d,x2 =2.575,P=0.011].超重/肥胖组的REE显著高于正常组[(5066.8±1 029.3)kJ/d比(4 556.4±799.1)kJ/d,x2=2.979,P=0.004],但两组TEE差异无统计学意义[(7 819.9±728.0) kJ/d比(7 803.2±1 092.0) kJ/d,x2=0.770,P=0.939].Logistic回归分析显示,透析液吸收热量和饮食脂肪摄入量是超重/肥胖的危险因素(OR=1.003,95％ CI=1.000 ～1.007,P=0.029;OR=1.024,95％ CI=1.003 ～1.046,P=0.027).结论 与BMI正常的CAPD患者比较,超重和肥胖患者饮食脂肪摄入量和从透析液中吸收的葡萄糖多,但TEE差异无统计学意义,提示超重/肥胖的CAPD患者处于能量正平衡状态,应减少高浓度葡萄糖透析液使用,并鼓励体育锻炼.     

10～12岁正常体重儿童能量代谢的研究

目的测定10～～12岁正常体重儿童的能量代谢.方法对正常体重儿童进行基础代谢、休息代谢以及能量摄入量和全日总能量消耗的测定.结果10～12岁正常体重儿童的基础代谢能量消耗为(212.63±20.54)kJ/h,休息代谢能量消耗为(227.27±23.52)kJ/h;基础代谢能量消耗实测值与用Schofield公式计算的结果没有显著性差异;男女童基础代谢与身高、体重、体表面积、体质指数、瘦体重、体脂肪呈显著正相关;10～12岁正常体重儿童每日能量需要量估计值为8 977kJ/d.结论10～12岁正常体重儿童的基础代谢和休息代谢能量消耗分别为(212.63±20.54)和(227.27±23.52)kJ/h;Schofield公式仍然适合于计算我国10～12岁儿童的基础代谢能量消耗;10～12岁正常体重儿童每日能量需要量估计值为8 977 kJ/d.     

石家庄市轻体力活动集体就餐人群能量摄入量研究

目的了解石家庄市事业单位轻体力劳动成年人能量摄入量状况。方法在石家庄市某事业单位选择三餐在食堂用餐的处于轻体力活动水平的38名成年人作为调查对象。采用称重记录法调查其每日的膳食种类及摄入量,并通过查阅食物成分表计算每日的能量摄入量。结果每日能量摄入量男性为(9070.0±1497.5)kJ[(2167.9±357.9)kcal)],女性为(7669.9±1396.5)kJ[(1833.2±333.8)kcal)]。以公斤体重计算,男性组为(130.9±17.4)kJ/(kg.d),女性组为(139.0±25.8)kJ/(kg.d)。男女的每日能量摄入量均比我国2000年制定的轻体力活动成年人的RNI值低。此外,受试对象全天各餐之间摄能比分别为早餐18.6%、中餐41.5%、晚餐35.0%,其中早餐摄能比值偏低。结论中国轻体力劳动成年人能量摄入的RNI值可能偏高,在评价能量摄入量时应考虑体重因素的影响。     

我国南方成人能量代谢试验膳食制备及分析

目的探讨成人能量代谢试验中"代表性膳食"的制备方法,为研究成人每日能量摄入量提供可靠的技术手段和方法。方法采取连续7d24h膳食登记法进行膳食问卷调查,获得重现率较高的代表性食物作为食谱中食物选择的重要依据。按照能量代谢试验中膳食制备的原则及要求为34名对象设计并制备三日循环膳食,经过预试对食谱进行调整并将制作过程规范化。根据每位对象的体重采取男性40kcal/kg·d和女性35kcal/kg·d确定能量及每种食物熟重的供给量。用称重法准确获得对象膳食的实际摄入量,并采用双份饭法进行留样,最后用化学分析法测得所有食物中各营养素及能量的含量,利用能量折合系数计算得到对象的膳食能量平均摄入量。结果根据膳食问卷调查的结果选出48种食用频率≥5次/周的食物作为参考,设计出符合能量代谢试验各项原则和要求的三日循环食谱。整个试验期间总体对象体重变化较稳定,整体可视作处于能量平衡状态。化学分析法测得总体对象的膳食能量平均摄入量为(8424±1616)kJ/d(2013±386kcal/d),其中男性平均为(9990±798)kJ/d(2388±191kcal/d),女性平均为(7032±384)kJ/d(1681±92kcal/d)。结论本研究试验膳食制备的方法具有可操作性,能够满足能量代谢试验的要求,保证试验结果的准确性。     

不同分娩方式对分娩后3～7天乳汁成分的影响分析

目的分析不同分娩方式对分娩后3~7d乳汁成分的影响。方法选择2016年12月至2017年12月在四川省妇幼保健院进行剖宫产及顺产的产妇各100名,分别设为剖宫产组和阴道分娩组。收集分娩后3~7 d的乳汁,测定、比较母乳中主要营养成分的含量。结果阴道分娩组乳汁中脂肪[(3.22±1.12)g/d L]、蛋白质[(2.95±1.31)g/d L]、干物质含量[(12.13±1.41)g/d L]及总能量[(65.50±6.15)kcal/d L]明显高于剖宫产组[(2.43±1.11)g/d L]、[(2.46±0.58)g/d L]、[(11.70±1.37)g/d L]、[(59.98±9.91)kcal/d L],差异有统计学意义(P0.05);而两组糖类含量[(6.11±0.71)g/d L]vs[(6.20±0.69)g/d L]比较差异无统计学意义(P0.05);应用多重线性回归分析显示分娩方式是3~7d乳汁中脂肪、蛋白质、干物质及总能量的主要影响因素(P0.05);而年龄、身高、分娩方式、新生儿性别和出生体重均对糖类没有影响(P0.05)。结论阴道分娩产妇3~7 d乳汁成分明显优于剖宫产产妇,应积极鼓励阴道分娩。     

石家庄农民秋季能量摄入量抽点调查分析

目的 抽点调查分析石家庄农村成年人能量摄入量和能量构成情况,为我国修订新的营养标准提供科学依据.方法 抽取石家庄市某郊县,随机抽取32名散居成年人作为调查对象.采用24h膳食回顾法结合烹调油和食用糖记录法进行入户调查,通过查阅食物成分表计算每日的能量摄入量和能量成分.结果 每日能量摄入量男性为(11 449.4±2 538.8) kJ即(2 736.5±606.8) kcal,女性为(7 823.8±1 461.7)KJ即(1 869.9±349.3) kcal;每日摄入蛋白质、脂肪和碳水化合物男性组分别为(80.13±15.43)、(86.70±32.55)和(399.17±108.05)g;女性组分别为(53.84±11.68)、(64.67±23.38)和(272.92±46.64)g.与我国2000年制定的推荐摄入量(recommended nutrient intakes,RNI)比较,女性组能量摄入量低于轻体力活动RNI值,女性组蛋白质摄入量低于RNI值.结论 本抽点调查农村女性居民的能量摄入量低于我国轻体力活动RNI值,男女居民均需增加能量成分中蛋白质的比例.     

对30名青年女性看电视和看书时能量消耗的研究

目的 测量青年女性在看电视和看书时的能量消耗.方法 通过问卷调查、常规体验、血常规、肝功能、甲状腺激素的测定结果挑选出青年女性30名,利用意大利产的心肺功能测试仪k4b2对学员的看书和看电视时能量消耗进行测定,并对其基础代谢率和静息代谢率进行测定.结果 看书时的能量消耗为(226.35±56.07)kJ/h,心率为(69±5)次/min,看电视能量消耗为(220.79±65.69)kJ/h,心率为(68±5)次/min;基础代谢率为(178.53±53.51)kJ/h,心率为(62±6)次/min,静息代谢率为(214.76±44.56)kJ/h,心率为(65±6)次/min.结论 看书的能量消耗要大于看电视的,但看书和看电视能量消耗差别较少,对于青年女性来讲,两者接近于静息代谢的能量消耗,它们均属于极轻体力活动.     

Use of [14C]-sodium bicarbonate/urea to measure physical activity induced increases in total energy expenditure in free-living healthy males

The aim of this study was to evaluate the utility of the [(14)C]-sodium bicarbonate/urea technique to detect physical activity-induced increases in total energy expenditure in free-living healthy men. Thirteen healthy males aged 34.1 +/- 11.7 yrs with body mass index 24.1 +/- 3.1 kg/m(2) were studied on three separate occasions, during which [(14)C]-bicarbonate was infused over 48-hours and urine was collected during the second 24-hours. On three separate occasions and in random order, subjects either remained sedentary, or performed a bout of physical activity on an electro-magnetically braked cycle ergometer sufficient to increase energy expenditure by 7% or 11% above predicted sedentary total energy expenditure. Urine samples were analyzed to evaluate the amount of [(14)C]-bicarbonate incorporated into urinary urea, thereby reflecting the amount of CO(2) produced per day, and upon conversion, the number of kilojoules of energy expended in 24-hours. All 13 subjects successfully completed the two physical activity treatments and there were no adverse events. As measured by the [(14)C]-urea assay, mean total energy expenditure values were not significantly different between sedentary activity (17902 +/- 905 kJ/day), the physical activity treatment designed to increase TEE by 7% (17701 +/- 594 kJ/day) and the physical activity treatment designed to increase TEE by 11% (18538 +/- 485 kJ/day) (P=0.668). In conclusion, although the [(14)C]-sodium bicarbonate/urea technique was well tolerated and did not interfere with normal daily activities, it was not able to accurately measure physical activity-induced increases in EE in the range of 7-11% above predicted sedentary total energy expenditure.     

Physical activities and energy expenditures of institutionalized Japanese elderly women

The daily energy expenditure and physical activity index of institutionalized Japanese elderly women were measured. One hundred and thirteen Japanese elderly women (aged 79.5 -/+ 7.0 y) who live in institutions for the elderly and receive meal services participated voluntarily. A dietary survey, energy metabolic study, and time study were carried out over three consecutive days, and the basal metabolic rate (BMR) and energy expenditure by physical activity were measured. The intensity of daily physical activity was based on the physical activity index (PAI: total/basal energy expenditure). The mean BMR was 881 +/- 145 kcal/d (20.9 +/- 3.8 kcal/kg BW). The PAI in individuals ranged from 1.01 to 1.57, the mean value was 1.26 +/- 0.14, and 64% of the subjects examined showed a lower value than 1.3 of PAI. From these values, the mean total energy expenditure was calculated as 1,112 +/- 231 kcal/d (26.2 +/- 5.2 kcal/kg BW).     

Body movement and physical activity energy expenditure in children and adolescents: how to adjust for differences in body size and age

BACKGROUND: Physical activity data in children and adolescents who differ in body size and age are influenced by whether physical activity is expressed in terms of body movement or energy expenditure. OBJECTIVE: We examined whether physical activity expressed as body movement (ie, accelerometer counts) differs from physical activity energy expenditure (PAEE) as a function of body size and age. DESIGN: This was a cross-sectional study in children [n = 26; (+/-SD) age: 9.6 +/- 0.3 y] and adolescents (n = 25; age: 17.6 +/- 1.5 y) in which body movement and total energy expenditure (TEE) were simultaneously measured with the use of accelerometry and the doubly labeled water method, respectively. PAEE was expressed as 1) unadjusted PAEE [TEE minus resting energy expenditure (REE); in MJ/d], 2) PAEE adjusted for body weight (BW) (PAEE. kg(-1). d(-1)), 3) PAEE adjusted for fat-free mass (FFM) (PAEE. kg FFM(-1). d(-1)), and 4) the physical activity level (PAL = TEE/REE). RESULTS: Body movement was significantly higher (P = 0.03) in children than in adolescents. Similarly, when PAEE was normalized for differences in BW or FFM, it was significantly higher in children than in adolescents (P = 0.03). In contrast, unadjusted PAEE and PAL were significantly higher in adolescents (P < 0.01). CONCLUSIONS: PAEE should be normalized for BW or FFM for comparison of physical activity between children and adolescents who differ in body size and age. Adjusting PAEE for FFM removes the confounding effect of sex, and therefore FFM may be the most appropriate body-composition variable for normalization of PAEE. Unadjusted PAEE and PAL depend on body size.     

Seasonal variation in total energy expenditure and physical activity in Dutch young adults

OBJECTIVE: The impact of season on energy expenditure and physical activity is not well quantified. This study focused on summer-winter differences in total energy expenditure (TEE) and physical activity. RESEARCH METHODS AND PROCEDURES: Twenty-five healthy Dutch young adults, living in an urban environment, were measured in the summer season and the winter season. TEE was measured using doubly labeled water, and sleeping metabolic rate (SMR) was measured during an overnight stay in a respiration chamber. Subsequently, the physical activity level (PAL = TEE/SMR) and activity-related energy expenditure [(0.9 x TEE) - SMR] were calculated. Maximal mechanical power (Wmax) was determined with an incremental test on a cycle ergometer. Body composition was measured with hydrostatic weighing and deuterium dilution using Siri's three-compartment model. RESULTS: There was no difference in TEE between seasons. PAL was higher in summer than in winter (1.87 +/- 0.22 vs. 1.76 +/- 0.18; p < 0.001), and the difference was higher for men than for women (0.20 +/- 0.14 vs. 0.05 +/- 0.16; p = 0.04). The difference in PAL between seasons was dependent on the initial activity level. There was a strong linear relation (R2 = 0.48) between PAL and physical fitness (Wmax/fat-free mass), but Wmax/fat-free mass did not change between seasons in response to the lower PAL in winter. DISCUSSION: The extent of the changes in PAL is of physiological significance, and seasonality in physical activity should be taken into account when studying physical activity patterns or relationships between physical activity and health.     

Estimated energy expenditure and physical activity patterns of adolescent distance runners

The purpose of this study was to examine the estimated total energy expenditure (TEE) and physical activity patterns of adolescent distance runners. Twenty-eight (20 male, 8 female) adolescent distance runners self-reported their daily physical activity with the Bouchard 3-d diary. Mean values for TEE, 57.4 +/- 11.6 and 51.0 +/- 9.8 kcal x kg(-1) x d(-1), and activity energy expenditure (AEE), 26.7 +/- 10.4 and 21.0 +/- 8.8 kcal x kg(-1) x d(-1), when expressed per kilogram body mass were not significantly different between males and females, respectively (P = 0.18). When expressed in absolute terms, TEE, 3609 +/- 927 and 2467 +/- 426 kcal/d, and AEE, 1688 +/- 746 and 977 +/- 269 kcal/d, were significantly higher in males than in females, respectively. The results document the energy expenditure and self-reported physical activity of adolescent distance runners and might be used to address recommendations for adequate dietary energy requirements in this group, which in turn is important for energy balance in the context of normal growth, health, and physical performance.     

广东省某高校大学生能量消耗研究

为了解我国南方地区现阶段健康大学生的能量消耗状况 ,为大学生能量供给提供参考 ,随机抽取广东某高校健康在校大学生 6 1人作为研究对象 (男 30人 ,女 31人 ) ,用间接测热法测定基础代谢 ,用全天活动时间记录法进行全天活动调查 ,采用WHO报告的要因加算法估算全天总能量消耗量。结果显示 ,男女大学生的基础代谢率分别为 (15 8 0 3± 7 85 )kJ (m2 ·h)和 (14 5 0 5± 10 14 )kJ (m2 ·h) ,全天总消耗量男女大学生分别为 (10 389 2 3± 15 19 90 )kJ d和 (792 1 15± 96 1 4 1)kJ d。结果提示我国南方地区现阶段健康大学生全天总能量消耗符合我国“轻体力劳动成人”能量供给量的标准     

Arg64 beta3-adrenoceptor variant and the components of energy expenditure

OBJECTIVE: To determine Trp64Arg beta(3)-adrenoceptor genotype-specific differences in the components of energy expenditure. HYPOTHESIS: We hypothesized that resting metabolic rate (RMR) and physical activity levels would be lower and that thermic effect of feeding (TEF) would be higher in those with the Arg64 allele. RESEARCH METHODS AND PROCEDURES: RMR and TEF were measured by indirect calorimetry, physical activity by questionnaire, and total energy expenditure by the doubly labeled water method. Genotype-specific measures were compared using ANOVA and analysis of covariance (ANCOVA). RESULTS: RMR in Arg64 homozygotes was significantly lower than in Trp64 homozygotes [Arg64, 1373 +/- 259 kcal/d (n = 15) vs. Trp64Arg, 1538 +/- 238 kcal/d (n = 25) vs. Trp64, 1607 +/- 290 kcal/d (n = 22); p < 0.01]. TEF was significantly higher in Arg64 homozygotes compared with Trp64 homozygotes (Arg64, 359 +/- 28 kcal/d; Trp64Arg, 322 +/- 22 kcal/d; and Trp64, 279 +/- 23 kcal/d; p < 0.05). No differences were identified between genotypes in physical activity or in total energy expenditure. DISCUSSION: Our results suggest that the Arg64 beta(3)-adrenoceptor allele contributes significantly to the genetic variability in both RMR and TEF.     

Physical activity levels are low in free-living adults with chronic paraplegia

OBJECTIVES: To compare physical activity levels (PALs) of free-living adults with chronic paraplegia with World Health Organization recommendations and to compare energy expenditure between persons with complete vs. incomplete paraplegia. RESEARCH METHODS AND PROCEDURES: Twenty-seven euthyroid adults (17 men and 10 women) with paraplegia (12.5 +/- 9.5 years since onset; 17 with complete lesions and 10 with incomplete lesions) participated in this cross-sectional study. Resting metabolic rate was measured by indirect calorimetry and total daily energy expenditure (TDEE) by heart rate monitoring. PAL was calculated as TDEE/resting metabolic rate. Total body water was measured by deuterium dilution and fat-free mass (FFM) and fat mass (FM) by calculation (FFM = total body water/0.732; FM = weight - FFM). Obesity was defined using the following percentage FM cutoffs: men 18 to 40 years >22% and 41 to 60 years >25%; and women 18 to 40 years >35% and 41 to 60 years >38%. RESULTS: Nineteen subjects (70.4%; 13 men and six women) were obese. Fifteen subjects (56%) engaged in structured physical activity 1.46 +/- 0.85 times during the observation period for a mean of 49.4 +/- 31.0 minutes per session. Despite this, mean PAL of the group was 1.56 +/- 0.34, indicative of limited physical activity. TDEE was 24.6% lower in subjects with complete paraplegia (2072 +/- 505 vs. 2582 +/- 852 kcal/d, p = 0.0372). DISCUSSION: PAL of the group was low, indicating that persons with paraplegia need to engage in increased frequency, intensity, and/or duration of structured physical activity to achieve a PAL >/=1.75 and, thereby, to offset sedentary activities of daily living.     

Total energy expenditure and physical activity level in healthy young Swedish children 9 or 14 months of age

OBJECTIVES: To measure total energy expenditure (TEE) and total body water (TBW) in healthy Swedish children 9 or 14 months of age. To compare their TEE with current recommendations for energy intake. To define their body composition and relate this to energy expenditure. DESIGN:: Children were investigated at 9 or 14 months. The following variables were measured: TEE and TBW (by the doubly labelled water method), weight and length. Total body fat (TBF), sleeping metabolic rate, activity energy expenditure and physical activity level (PAL) were calculated. SUBJECTS: Thirty infants 9 months of age and 29 children 14 months of age. RESULTS:: TEE was 323+/-38, 322+/-29, 313+/-23 and 331+/-28 kJ/kg/day in 9-month-old girls, 9-month-old boys, 14-month-old girls and 14-month-old boys, respectively. At 9 months of age girls and boys contained 29.6+/-4.8 and 29.7+/-4.5% TBF, respectively. At 14 months the corresponding figures were 29.1+/-4.3 and 28.2+/-4.3%. There was a significant negative relationship between PAL and %TBF (r=-0.81, P<0.001, n=59). CONCLUSIONS: Measured TEE plus calculated energy cost of growth confirm previous estimates that the physiological energy requirements of children 9 and 14 months of age are 15-20% lower than current recommendations for energy intake. One possible interpretation of the relationship between PAL and %TBF is that children with a high TBF content are less physically active than children with less TBF. However, this relationship needs further studies.     

Physical activity levels in a sample of Oxford school children aged 10-13 years

OBJECTIVE: To determine physical activity levels (PAL) in children aged between 10 and 13 y. DESIGN: Cross-sectional study of physical activity levels on school days, with and without physical education (PE) lessons and at weekend. Data were collected using self-reported activity diaries. SETTING: The children were recruited from a middle school in Oxford. Basal metabolic rate (BMR) and anthropometry were measured in the school. SUBJECTS: Thirty-eight children (12 boys and 26 girls), aged 10-13 y, returned completed activity diaries. PAL values were calculated by applying physical activity ratios (PAR) to the time spent on each activity. BMR and anthropometry were measured within 20 d of activity diary completion. RESULTS: The mean +/-s.d. (range) PAL values for all children were 1.52+/-0.08 (1.34-1.71), 1. 50+/-0.05 (1.44-1.57) for boys and 1.53+/-0.10 (1.34-1.71) for girls. The lowest PAL value (1.48+/-0.13, mean +/-s.d.) was observed in girls on school days without PE lessons. The lowest PAL value in boys (1.46+/-0.13, mean +/-s.d.) was observed at the weekend. PE lessons made a significant difference to the PAL values for boys (1. 58+/-0.09) and girls (1.60+/-0.12). A wide range of PAL values (1. 20-1.87) was recorded in these children. The total energy expenditure for the boys was slightly lower than the estimated average requirements (EAR) predicted by the Department of Health (8. 71+/-0.96 MJ compared with 8.86 MJ/d) for this age group. The girls had a higher average energy expenditure than the predicted EAR (8. 47+/-1.00 MJ/d compared with 7.885). CONCLUSIONS: The children in this study may be classified as light to moderately active with PAL values ranging from 1.20 to 1.87. The promotion of physical activity in childhood will have beneficial effects for the child and their future wellbeing. Programmes aimed at preventing obesity in children should encourage physical activity as well as promoting appropriate dietary changes.