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1.
OBJECTIVES: To evaluate the ratio of energy intake to basal metabolic rate (EI/BMR) among young female Japanese adults, and to compare the lifestyle and dietary characteristics between relatively low and high reporters. DESIGN: Dietary intakes were assessed over a 1-month period with a validated, self-administered, diet history questionnaire, and lifestyle variables were assessed by a second questionnaire designed for this survey. The ratio of EI/BMR was calculated from reported energy intake and estimated basal metabolic rate. SUBJECTS: In total, 1889 female Japanese university students aged 18-20 years who were enrolled in dietetics courses. RESULTS: Ninety-five per cent of the subjects were classified into a non-obese group (body mass index (BMI) <25 kg m(-2); mean+/-standard deviation (SD): 20.8+/-2.6 kg m(-2)). EI/BMR was 1.43+/-0.40 (mean+/-SD). Sixty-eight per cent of the subjects showed an EI/BMR level below the possibly balanced value of 1.56, 37% showed EI/BMR below the minimum survival value of 1.27 and 2% of the subjects showed EI/BMR exceeding the maximum value for a sustainable lifestyle of 2.4. BMI, body weight and BMR decreased significantly with the increase in EI/BMR (P<0.001). The percentage of energy from carbohydrate was significantly higher, whereas those from fat and protein were significantly lower, among the lower EI/BMR groups. As for food groups, a significantly declining trend from the lowest to the highest EI/BMR groups was observed for cereals. CONCLUSION: Underreporting, rather than overreporting, of energy intake was predominant in this relatively lean Japanese female population. BMI was the most important factor affecting the reporting accuracy of energy intake.  相似文献   

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OBJECTIVE: To develop a quantitative food-frequency questionnaire (QFFQ) for the Barbados National Cancer Study (BNCS) that will permit examination of associations of diet with breast and prostate cancer. DESIGN: Population intake data from the year 2000 Barbados Food Consumption and Anthropometric Surveys (BFCAS 2000) were used to derive a list of foods consumed by the population. A 192-item draft QFFQ was developed from this list. SETTING: Barbados, West Indies provides an ideal environment to understand cancer risk in African-origin populations, with high relevance to African-Americans. The BNCS is a population-based case-control study examining risk factors for breast and prostate cancer in such populations. SUBJECTS: A total of 1600 persons, 18 years and older, completed a 24-hour recall in the BFCAS 2000. Fifty of 63 randomly selected residents (79% response rate) gave additional updated information on foods consumed. RESULTS: The 50 participants provided a one-time 24-hour recall and completed the draft QFFQ. The final instrument contains 148 items: breads, cakes, cereals = 17; rice, pastas, noodles = 8; dairy = 10; meat, fish, poultry = 42; fruit = 16; vegetables = 26; soft drinks = 14; alcoholic beverages = 5; others = 10. Additional questions include supplement use and food preparation methods such as grilling. CONCLUSION: The final instrument is concise, complete and the most up-to-date for assessing the food and nutrient intake of African-origin Barbadians and the associations with breast and prostate cancer.  相似文献   

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OBJECTIVE: To compare methods used to assess the validity of nutrient intake data obtained from a food-frequency questionnaire (FFQ), using folate and vitamin B12 as nutrient examples. DESIGN: Cross-sectional sample from a population cohort. SETTING: Two postcode areas west of Sydney, Australia. SUBJECTS: In total, 2895 people aged 49 years and older provided dietary data using a semi-quantitative FFQ (79% of 3654 subjects examined). The validity of the FFQ was assessed against three 4-day weighed food records (WFRs) completed by 78 people (mean age 70 years). RESULTS: Folate and vitamin B12 validity data were assessed using different methods. The Spearman ranked correlations (energy-adjusted) were 0.66 for folate and 0.38 for vitamin B12. Using the Bland-Altman method, following loge transformation, no linear trend existed between the differences and means for folate and vitamin B12. Large differences existed between the FFQ and WFR in individual cases, particularly for vitamin B12. Finally, data were divided into quintile categories for the test and reference method: 79% classified folate within one quintile, 65% classified vitamin B12 within one quintile; there was no gross misclassification for folate and only 3% misclassification for vitamin B12. CONCLUSIONS: Different methods of analysis provided different information about the validity of the FFQ. Correlation coefficients should not be used alone to assess the validity of nutrient data, but should be used in conjunction with Bland-Altman analyses. Depending on the use of the data, additional assessment of classification categories is recommended. This worked example demonstrates that absolute intakes of folate and vitamin B12 should be used with caution.  相似文献   

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Nickel (Ni), an essential micronutrient, is toxic to plants and animals at elevated levels. Fewer data are available on the dynamics of Ni than for trace metals such as Cu and Zn. Dietary intake is the major source of Ni, but almost no information is available on dietary intake for Asian populations whose diet contains much less animal products and processed foods than in Western countries. In south‐eastern China, most food is grown on peri‐urban agricultural land and thus, food crops from these areas should be the major source of dietary Ni. A large‐scale survey of Ni in soils and edible crops, including 515 sites and 24 crop species from 10 crop groups, was conducted in Fujian Province, SE China, to assess Ni intake for a typical SE Asian diet. Correlation, principal component analysis (PCA) and data mining were used to identify soil and plant factors that determine Ni accumulation in crops. Both soil Ni content and plant species contributed to Ni accumulation. Crop Ni (Nicrop) was positively correlated with soil Ni DTPA‐extractible (diethylenetriaminepentaacetic acid) (NiDTPA) for many crops. PCA did not identify strong relations between soil‐to‐crop transfer factors and any soil properties. Stepwise linear correlations found positive correlations between Nicrop and NiDTPA; however, relationships between Nicrop and both silt content and pH varied between crops. Dietary intake of foods containing mean Ni content could lead to health risks, especially for children. It was concluded that sandy soils, rich in organic matter with a large Ni content, are unsuitable for the production of rice and legumes.  相似文献   

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OBJECTIVES: To characterise the diet of First Nations in north-western Ontario, highlight foods for a lifestyle intervention and develop a quantitative food-frequency questionnaire (QFFQ). DESIGN: Cross-sectional survey using single 24 h dietary recalls. SETTING: Eight remote and semi-remote First Nations reserves in north-western Ontario. SUBJECTS: 129 First Nations (Oji-Cree and Ojibway) men and women aged between 18 and 80 years. RESULTS: The greatest contributors to energy were breads, pasta dishes and chips (contributing over 20 % to total energy intake). 'Added fats' such as butter and margarine added to breads and vegetables made up the single largest source of total fat intake (8.4 %). The largest contributors to sugar were sugar itself, soda and other sweetened beverages (contributing over 45 % combined). The mean number of servings consumed of fruits, vegetables and dairy products were much lower than recommended. The mean daily meat intake was more than twice that recommended. A 119-item QFFQ was developed including seven bread items, five soups or stews, 24 meat- or fish-based dishes, eight rice or pasta dishes, nine fruits and 14 vegetables. Frequency of consumption was assessed by eight categories ranging from 'Never or less than one time in one month' to 'two or more times a day'. CONCLUSION:We were able to highlight foods for intervention to improve dietary intake based on the major sources of energy, fat and sugar and the low consumption of fruit and vegetable items. The QFFQ is being used to evaluate a diet and lifestyle intervention in First Nations in north-western Ontario.  相似文献   

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Arsenic (As) species were quantified by HPLC-HG-AFS in water and vegetables from a rural area of West Bengal (India). Inorganic species predominated in vegetables (including rice) and drinking water; in fact, inorganic arsenic (i-As) represented more than 80% of the total arsenic (t-As) content. To evaluate i-As intake in an arsenic affected rural village, a food survey was carried out on 129 people (69 men and 60 women). The data from the survey showed that the basic diet, of this rural population, was mainly rice and vegetables, representing more than 50% of their total daily food intake. During the periods when nonvegetarian foods (fish and meat) were scarce, the importance of rice increased, and rice alone represented more than 70% of the total daily food intake. The food analysis and the food questionnaires administrated led us to establish a daily intake of i-As of about 170 microg i-As day (-1), which was above the tolerable daily intake of 150 microg i-As day (-1), generally admitted. Our results clearly demonstrated that food is a very important source of i-As and that this source should never be forgotten in populations depending heavily on vegetables (mainly rice) for their diet.  相似文献   

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冬小麦上短控释期尿素的适宜施用量与施用方法研究   总被引:1,自引:3,他引:1  
【目的】控释尿素受土壤温度、 水分等环境条件的影响,应用效果不一。对比相同施氮量下一次性基施控释尿素与尿素分期施用,以及控释尿素和普通尿素追施对冬小麦籽粒产量、 品质, 氮肥利用率及综合经济效益的影响,可为控释尿素的合理施用提供理论和技术依据。【方法】采用大田试验,选用新麦26为供试材料,随机区组试验设计,调查了冬小麦籽粒产量、 主要品质性状、 氮肥利用率及经济效益。设两个试验,试验1: 控释尿素和普通尿素各设5个氮肥水平,即N 0、 120、 160、 200和240 kg/hm2; 试验2: 设不施氮肥、 N 200 kg/hm2总氮量下普通尿素和控释尿素均40%返青期追施3个处理。【结果】 1)与不施氮(CK)相比,控释尿素和普通尿素均可显著提高小麦籽粒产量,且随着施氮量的增加而增加,其中以分期施用普通尿素N 240 kg/hm2处理籽粒产量最高。相同施氮量下,分期施用普通尿素处理小麦籽粒产量显著高于一次性基施控释尿素处理(N 160 kg/hm2除外)。然而,返青期追施控释尿素处理小麦籽粒产量显著高于同期追施普通尿素处理,增产率达15.8%; 2)相同施氮量下,分期施用普通尿素处理较一次性基施控释尿素处理的小麦籽粒容重、 蛋白质含量、 水分含量、 湿面筋含量均有所提高,且两种尿素处理间籽粒容重在N 160 kg/hm2和N 200 kg/hm2时差异达显著水平。然而,返青期追施控释尿素处理小麦籽粒容重、 湿面筋含量、 蛋白质含量等品质指标显著高于同期追施普通尿素处理; 3)两种尿素处理氮肥农学利用率和氮肥偏生产力随施氮量的增加而降低,在相同施氮量下分期施用普通尿素处理显著高于一次性基施控释尿素处理。此外,与分期施用普通尿素处理相比,一次性基施控释尿素处理减少了小麦拔节期追肥人工成本投入,但由于一次性基施控释尿素处理籽粒产量较低和氮肥价格较高,导致经济效益相对较低。然而,试验2结果表明,返青期追施控释尿素处理氮素利用率(氮肥农学效率、 氮肥偏生产力及氮素回收率)和经济效益显著高于同期追施普通尿素处理。【结论】本研究地区较适宜的推荐氮肥施用量为N 200 kg/hm2,一次性基施控释尿素较适宜于劳力欠缺的农户,而对于个别劳力充足的农户则适宜采用分期追施普通尿素或者小麦返青期追施控释尿素的氮肥管理技术。因此,在当前农村劳动力日益减少,用工成本日益增加以及种粮比较效益持续降低的大环境下,氮素肥料合理选择和施用技术要依据实际情况而定。  相似文献   

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OBJECTIVE: This study reports on the energy, macro- and micronutrient intakes of a true longitudinal group of 143 urban black South African children from the Birth-to-Twenty (Bt20) study at two interceptions (2000 and 2003) when they were 10 and 13 years old, respectively. METHODS: Subjects resided in the urban Johannesburg/Soweto area of the Gauteng Province in South Africa. Dietary intake was assessed using a semi-quantitative food-frequency questionnaire. The coded data were analysed using SAS. RESULTS: Mean daily intake of energy, all six macronutrients and most micronutrients (17/19) increased from 2000 to 2003. Of the 19 micronutrients investigated, the mean daily intake of eight (calcium, iron, zinc, vitamin A, riboflavin, nicotinic acid, pantothenic acid and biotin) fell below the recommended dietary allowance (RDA) at both interceptions. More than 70% of the children consumed less than the RDA for these same eight nutrients. From 2000 to 2003, there was a decrease in the percentage of children falling below the RDA for energy (from 73 to 59%), but an increase in the percentage of children falling below the RDA for most of the micronutrients. There was a positive percentage change in mean daily intake for all 26 macro- and micronutrients from 2000 to 2003. CONCLUSION: Mean daily intake of nutrients increased from 2000 to 2003, but intakes for most micronutrients were still below the RDA at both interceptions for a large percentage of the children. The study has provided valuable information on the nutrient intake and change in intake over time among a longitudinal group of South African adolescents.  相似文献   

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Specialization within agriculture has been a key factor in increasing farm income. The production systems have become increasingly simple, since farmers only grow a small number of crops which have a favourable market price. However, monocultural systems require increasing use of agrochemicals leading to unsustainable environmental costs. In this work, the soil fertility of two plots in a crop rotation previously grown for 5 years as pasture or maize monoculture was evaluated. In the pasture, the upper 0–20 cm soil layer sequestered 17.4 Mg organic C ha?1 and accumulated 403 kg N ha?1 more than under maize monoculture. Analytical data from pot experiments showed that soil samples from the pasture plot released significantly more mineral N than soil samples from the maize monoculture. Maize dry matter (DM) yields in 2012 and 2013 were 15.3 and 10.0 Mg ha?1 in the pasture plot and 8.8 and 8.4 Mg ha?1 in the maize monoculture plot. Nitrogen recoveries by maize were 175.4 and 68.0 kg ha?1 in the pasture and 78.3 and 50.3 kg ha?1 in the maize monoculture plot. The pool of organic matter accumulated during the pasture phase immobilized important nutrients which benefited the succeeding crop as the organic substrate was mineralized.  相似文献   

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通过野外植被调查研究黄土丘陵区草原带退耕地植被在自然恢复过程中的演替规律及物种多样性特征,通过室内土壤样品分析土壤有机碳、全氮、碱解氮、速效磷含量及土壤脲酶、转化酶、磷酸酶、过氧化氢酶活性动态变化过程,并对植物多样性指数和土壤养分及酶活性进行相关分析。研究结果表明,黄土丘陵区草原带退耕地在长达75a的自然恢复过程中,植物群落演替以菊科(猪毛蒿)与黎科(虫实)等为主的一年生草本开始,逐步演替为多年生草本群落,最后形成以大针茅+长芒草为优势种的顶级草原群落,植物物种数总体上呈现增加趋势;物种多样性指数随退耕年限延长均呈波动性上升趋势;土壤养分及酶活性均随退耕年限的增长亦呈波动性上升趋势。自然恢复75a,Margalef指数、Shannon-Wienner指数及Pielous指数分别增加83.3%、31.8%、21.4%;土壤有机碳、全氮、碱解氮、速效磷含量分别增加了185.0%、164.8%、152.9%、109.8%;土壤脲酶、转化酶、碱性磷酸酶及过氧化氢酶活性分别增加了64.0%、7.8%、51.1%、11.8%。土壤养分及酶活性与Margalef指数、Shannon-Wienner指数之间存在显著正相关关系,与Pielous指数相关性不显著。  相似文献   

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The Lake Naivasha fishery is constituted by three introduced species, Sarotherodon leucostictus, Tilapia zillii and Micropterus salmoides. No indigenous species are now found in the lake. S. spilurus niger, another introduced species, and hybrids of S. s. niger × S. leucostictus, abundant in 1961, have almost completely disappeared.The annual catch of Sarotherodon-Tilapia and M. salmoides between 1968 and 1974 ranged from 109·2 to 1479·6 metric tons and 7·9 to 471·9 metric tons respectively.S. leucostictus is a bottom feeder (chironomid larvae 64°24%, detritus 20·58%), T. zillii feeds on aquatic macrophytes (76·62%) and M. salmoides feeds almost exclusively on crayfish (78·25%). A major portion of the fish food present in the lake is left unused.The yield, which has progressively declined since 1968, could be increased considerably by introducing certain management measures. These are discussed.  相似文献   

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OBJECTIVE: We evaluated the performance of the food-frequency questionnaire (FFQ) administered to participants in the US NIH-AARP (National Institutes of Health-American Association of Retired Persons) Diet and Health Study, a cohort of 566 404 persons living in the USA and aged 50-71 years at baseline in 1995. DESIGN: The 124-item FFQ was evaluated within a measurement error model using two non-consecutive 24-hour dietary recalls (24HRs) as the reference. SETTING: Participants were from six states (California, Florida, Pennsylvania, New Jersey, North Carolina and Louisiana) and two metropolitan areas (Atlanta, Georgia and Detroit, Michigan). SUBJECTS: A subgroup of the cohort consisting of 2053 individuals. RESULTS: For the 26 nutrient constituents examined, estimated correlations with true intake (not energy-adjusted) ranged from 0.22 to 0.67, and attenuation factors ranged from 0.15 to 0.49. When adjusted for reported energy intake, performance improved; estimated correlations with true intake ranged from 0.36 to 0.76, and attenuation factors ranged from 0.24 to 0.68. These results compare favourably with those from other large prospective studies. However, previous biomarker-based studies suggest that, due to correlation of errors in FFQs and self-report reference instruments such as the 24HR, the correlations and attenuation factors observed in most calibration studies, including ours, tend to overestimate FFQ performance. CONCLUSION: The performance of the FFQ in the NIH-AARP Diet and Health Study, in conjunction with the study's large sample size and wide range of dietary intake, is likely to allow detection of moderate (> or =1.8) relative risks between many energy-adjusted nutrients and common cancers.  相似文献   

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OBJECTIVE: To report on the variety and total number of food items recorded by a true longitudinal group of urban black South African children (n = 143) from the Birth-to-Twenty Study at five interceptions at the ages of 5 (1995), 7 (1997), 9 (1999), 10 (2000) and 13 (2003) years, respectively. METHODS: Dietary intake was assessed using a semi-quantitative food-frequency questionnaire. Frequencies were calculated per week, for each interception and for all five interceptions combined, using SAS. RESULTS: Five hundred and forty-six different individual food items were recorded 23 480 times for all five interceptions combined. The highest of 124 items was recorded in 1999 contributing 23% of the 546 items recorded. Each of the top 10 items (rice, stiff maize-meal porridge, chicken, sugar, sweets, tea, eggs, full-cream milk, carbonated beverages and oil) contributed between 2.5% and 3% and these items were recorded almost 600 times or more for all interceptions combined (n = 23 840). Rice and stiff maize-meal porridge were the top items recorded 684 and 676 times, both contributing 2.87% and 2.84%, respectively. The variety of food items and the ratio of the food groups to the total number of foods recorded in the present study were not significantly different but the denominators decreased over the five interceptions. CONCLUSION: The variety of food items recorded did not vary between 1995 and 2003 - the fact that new items were not added to the questionnaire as the children grew older could have contributed to this phenomenon. However, there was a difference in the ranking of these items that may suggest a change in eating patterns.  相似文献   

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