京郊密云县农业生态系统蛋白人口承载力模型分析

农业生态系统蛋白人口承载力不仅是农业生态学系统生产力研究的重要方面,而且是制定我国人口政策和食物战略的重要依据。中央曾指出:要把我国人民的膳物结构问题作为战略问题来考虑。分析我国的膳食特点可概括为“一够两缺”(即热量够,蛋白质和脂肪缺)温饱型营养水平。食物蛋白质的改善是我国膳食结     

膳食蛋白质摄入与2型糖尿病关系的病例对照研究

目的：探讨膳食蛋白质与2型糖尿病（T2DM）之间的相关关系。方法：采用年龄与性别匹配的病例对照研究,在西安市某社区招募符合纳入标准的T2DM患者288例和对照552例。采用膳食频率调查表,根据食物摄入频率及数量计算膳食蛋白质摄入量和供能比。通过健康危险因素问卷收集研究对象人口学、生活方式、疾病史等基本信息。采用单因素统计方法和多因素Logistic回归模型探究膳食蛋白质与成人T2DM的相关性。结果：参与者的平均年龄为62.0±9.8岁,膳食总能量和蛋白质日均摄入量分别为（2 204.3±852.5）kcal/d、（81.7±38.1）g/d。在总人群中,校正高血压、血脂异常等混杂因素后,总蛋白及动物蛋白供能比最高分位组T2DM罹患风险是最低组的1.92倍。动物蛋白与女性T2DM风险的比值比为2.33,而与男性T2DM无关。植物蛋白与T2DM无显著相关性。结论：膳食总蛋白,尤其是动物蛋白与T2DM罹患风险正相关,植物蛋白与T2DM没有显著关联性。在糖尿病防治中应考虑饮食蛋白质的比例及种类。     

膳食干预对高胆固醇血症患者血脂和营养状况的影响

目的：探讨个体化膳食干预对高胆固醇血症患者血脂指标和营养状况的影响。方法：选取2013年6月—2014年12月收入北京友谊医院且诊断为高胆固醇血症的90例患者,膳食干预3个月,使用24 h膳食回顾调查法和食物频度法,分析调查对象每天膳食中热能及各种营养素的摄入量,与中国居民膳食推荐摄入量比较,分析膳食干预前后患者的饮食情况、血脂指标和相关营养指标的变化。结果：与每人每日各类食物适宜摄入量相比,高胆固醇血症患者在膳食干预前,蔬菜、水果、豆类食物的摄入量偏少,肉类、蛋、奶、油脂类食物摄入量偏高,营养素供能比例不适宜,蛋白质和脂肪供能比例偏高,碳水化合物供能比例偏低;与膳食干预前相比,膳食干预后每日谷类食物、肉类、鸡蛋、奶、油脂类的摄入量显著降低,蔬菜、水果、豆类的摄入量显著增加,摄入的总能量显著降低,摄入的蛋白质、脂肪的量及其供能比显著降低,动物蛋白的供能比显著降低,碳水化合物的摄入量及其供能比显著增加）;经过膳食干预后,高胆固醇血症患者的血清总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL-C）水平显著降低,血清高密度脂蛋白胆固醇（HDL-C）水平显著増高,患者的体质指数（BMI）显著降低,血清总蛋白（TP）、白蛋白（ALB）、血红蛋白（HGB）与膳食干预前相比差异无统计学意义。结论：高胆固醇血症患者通过改善膳食结构和降低体质指数,可以降低TC、TG、LDL-C等血脂指标,升高HDL-C,其营养状况不会受到影响。     

中国七城市学龄儿童蛋白质摄入情况研究

目的：通过横断面调查,描述中国7城市学龄儿童蛋白质摄入情况。方法：采用多阶段随机整群抽样和立意抽样结合的方法选取儿童618名,通过问卷调查获得其一般情况、通过24h膳食回顾调查获得其膳食情况。结果：调查对象整体的蛋白质摄入量为502±267g/d,不同年龄组间蛋白质摄入量存在差异（F=2425,P＜005）,11~12岁组最差、7~岁组最好。早餐、午餐和晚餐的蛋白质摄入量不同,早餐的蛋白质摄入量最少,中位数为125g/d;午餐和晚餐的蛋白质摄入量相近,中位数分别为232、224g/d,差异有统计学意义（F=58394,P＜001）。蛋白质的食物来源中,动物性食物占总蛋白质摄入的比例为522%、植物性食物占478%。动物性食物中对蛋白质摄入贡献最多的前5类食物分别为猪肉、蛋类、家禽类、鱼/贝/虾类、牛肉;植物性食物中对蛋白质摄入贡献最多的前5类食物分别为大豆/豆腐/其它豆制品、大米、烙饼/煎饼/烧饼/油饼、面条、面包/饼干。结论：7城市学龄儿童蛋白质摄入不足的发生率较高,蛋白质在三餐中的分配不均,摄入优质蛋白质（动物性食物、豆类及豆制品）的比例较为理想,但膳食结构尚需进一步优化。     

中国18~49岁育龄妇女能量和宏量营养素摄入状况分析

目的：评估中国18~49岁女性的膳食能量和宏量营养素摄入状况。方法：数据来源于2015年中国成人慢性病与营养监测（CNNHS 2015）。本研究对15 839名18~49岁育龄妇女进行24 h膳食回顾调查和家庭食用油和调味品称重等膳食调查,根据中国食物成分表（2004、2009版）计算能量和宏量营养素摄入量。结果：我国18~49岁女性碳水化合物和蛋白质供能比在正常推荐范围,但是脂肪供能比较高,膳食结构偏向西方膳食模式。结论：育龄妇女面临的膳食结构不合理问题值得关注,特别是生活在西部地区的女性。建议我国18~49岁育龄女性合理选择食物,改善饮食结构,控制脂肪的摄入。     

食物蛋白质的遗传修饰

用某些选定核酸碱基对插入或缺失的办法,对生产食物的机体的基因组的定向改变,可导致个别食物蛋白的一级结构的变化。结果产生的对变异后基因产物的理化性质或其对酶敏感性的修饰常叠加在内源正常蛋白质上。如果能够合成足够的新型蛋白质并使之与食物中蛋白质的基础水平相匹配,那么该食品系统的功能性质(如乳化、泡沫化、胶化等)会变得更     

居民食物消费特征及影响因素分析——基于全国20省居民食物消费调研

我国居民食物消费结构正处于调整升级阶段,研究食物消费特征和影响因素有助于预测需求和指导生产结构调整。根据全国20省居民家庭食物消费调研的数据,运用线性系统模型分析收入、价格、地区和偏好等因素对消费量的影响,结果显示：收入水平对城镇居民水产和奶类等食物影响最为显著,影响系数均为0.20;产区、地区差异、饮食结构和偏好等因素对消费量的影响较为明显。未来应该大力发展农业规模化、现代化,提高农业生产效率,增加农民收入;根据食物消费需求调整生产结构,重点发展畜禽业和水产养殖业;并且推广和引导健康的膳食模式。     

Food Funct:优质蛋白对人类的生长、发育和健康是必不可少的

正最近的报道称某些肉类蛋白质对你来说并不好,德州农工大学生态农业研究学院的科学家发现,食用充足的优质蛋白质对人类的生长、发育和健康是至关重要的。GuoyaoWu博士的研究发表在FoodFunction上。他的文章阐述了膳食蛋白质摄入量和人类健康的关系,他说动物性和植物性食物的适当     

126例维持性血液透析患者膳食调查

目的：通过膳食调查了解维持性血液透析患者饮食结构和膳食摄入量,评估各膳食营养素摄入量对血液透析患者营养需求的满足程度,为合理营养干预提供依据。方法：本课题以我国慢性肾脏病蛋白营养治疗共识（2005）及欧洲肠外肠内营养学会（ESPEN）的膳食指南为推荐量,采用24h膳食回顾法调查血透患者连续3d膳食摄入情况,分析食物来源和饮食结构,评价每日食物及每日营养素摄入量,比较各营养素摄入量与推荐量的差异性。结果：根据食物分类,血透患者日均摄入量排在前三位分别是蔬菜类（247.5g,占34%）、谷类（209g,占28.7%）和水果类（71.5g,占9.8%）,排在末三位分别是鱼类、豆类、蛋类（13.7g,占1.9%;22.2g,占3.0%;27.6g,占3.9%）;动物性食物是蛋白质摄入的主要食物来源（占62%）,植物性食物是钙、铁摄入的主要食物来源（占53%和69%）;与推荐量相比,血透患者除了维生素E和钠的摄入量大于推荐量外,日均总热卡和三大产热营养素（蛋白质、脂肪、碳水化合物）摄入量低于推荐量;部分维生素（维生素C、维生素B1、B2、B6）和部分矿物质（锌、硒、铁等）摄入量低于推荐量（P＜0.05）。结论：血透患者普遍存在膳食摄入不足的问题,大部分膳食营养素摄入量不能满足血透患者营养需求,建议加强饮食指导和营养支持。     

2016-2017年中国12-17岁儿童青少年能量及宏量营养素摄入状况

目的：分析2016—2017年中国12～17岁儿童青少年能量及宏量营养素摄入状况,为引导中国12~17岁儿童平衡膳食和合理营养提供科学依据。 方法：数据来源于2016—2017年中国儿童与乳母营养健康监测数据,采用多阶段分层随机抽样方法,在全国31省抽取275个监测点开展营养健康监测。膳食调查采用连续3 d 24 h膳食回顾法收集食物摄入信息,采用食物秤称重记录家庭或学校食堂连续3 d食用油和调味品的摄入量,依据《中国食物成分表》计算能量和三大宏量营养素的摄入量。结果：2016—2017年中国12～17岁儿童青少年膳食能量、碳水化合物、脂肪和蛋白质的平均每人日摄入量分别为1 995.0 kcal、253.8 g、84.5 g、61.4 g。碳水化合物、脂肪和蛋白质的供能比分别为50.6%、37.1%、12.3%。72.9%的儿童青少年脂肪供能比高于推荐值30%、48.0%的儿童青少年碳水化合物供能比低于推荐值50%、22.6%的儿童青少年蛋白质供能比低于推荐值10%。儿童青少年膳食脂肪来源于食用油、动物性食物和植物性食物的比例分别为43.9%、36.6%、19.6%。12～17岁儿童青少年平均每人日膳食能量、碳水化合物、脂肪和蛋白质的摄入量均随年龄的增长而增加,男生高于女生,能量、蛋白质和脂肪摄入量存在城乡差异,城市高于农村（P<0.01）。城市儿童青少年蛋白质供能比达到中国居民膳食宏量营养素可接受范围（AMDR）的比例高于农村（P<0.01）。结论：中国12～17岁儿童青少年每人日膳食能量基本满足,三大宏量营养素供能比不合理。能量、蛋白质和脂肪摄入量存在城乡差异,农村儿童脂肪供能比增幅过快亟待关注。     

Mapping the Influence of Food Waste in Food Packaging Environmental Performance Assessments

Scrutiny of food packaging environmental impacts has led to a variety of sustainability directives, but has largely focused on the direct impacts of materials. A growing awareness of the impacts of food waste warrants a recalibration of packaging environmental assessment to include the indirect effects due to influences on food waste. In this study, we model 13 food products and their typical packaging formats through a consistent life cycle assessment framework in order to demonstrate the effect of food waste on overall system greenhouse gas (GHG) emissions and cumulative energy demand (CED). Starting with food waste rate estimates from the U.S. Department of Agriculture, we calculate the effect on GHG emissions and CED of a hypothetical 10% decrease in food waste rate. This defines a limit for increases in packaging impacts from innovative packaging solutions that will still lead to net system environmental benefits. The ratio of food production to packaging production environmental impact provides a guide to predicting food waste effects on system performance. Based on a survey of the food LCA literature, this ratio for GHG emissions ranges from 0.06 (wine example) to 780 (beef example). High ratios with foods such as cereals, dairy, seafood, and meats suggest greater opportunity for net impact reductions through packaging‐based food waste reduction innovations. While this study is not intended to provide definitive LCAs for the product/package systems modeled, it does illustrate both the importance of considering food waste when comparing packaging alternatives, and the potential for using packaging to reduce overall system impacts by reducing food waste.     

The future of the global food system

Although food prices in major world markets are at or near a historical low, there is increasing concern about food security—the ability of the world to provide healthy and environmentally sustainable diets for all its peoples. This article is an introduction to a collection of reviews whose authors were asked to explore the major drivers affecting the food system between now and 2050. A first set of papers explores the main factors affecting the demand for food (population growth, changes in consumption patterns, the effects on the food system of urbanization and the importance of understanding income distributions) with a second examining trends in future food supply (crops, livestock, fisheries and aquaculture, and ‘wild food’). A third set explores exogenous factors affecting the food system (climate change, competition for water, energy and land, and how agriculture depends on and provides ecosystem services), while the final set explores cross-cutting themes (food system economics, food wastage and links with health). Two of the clearest conclusions that emerge from the collected papers are that major advances in sustainable food production and availability can be achieved with the concerted application of current technologies (given sufficient political will), and the importance of investing in research sooner rather than later to enable the food system to cope with both known and unknown challenges in the coming decades.     

Feeding the world healthily: the challenge of measuring the effects of agriculture on health

Agricultural production, food systems and population health are intimately linked. While there is a strong evidence base to inform our knowledge of what constitutes a healthy human diet, we know little about actual food production or consumption in many populations and how developments in the food and agricultural system will affect dietary intake patterns and health. The paucity of information on food production and consumption is arguably most acute in low- and middle-income countries, where it is most urgently needed to monitor levels of under-nutrition, the health impacts of rapid dietary transition and the increasing ‘double burden’ of nutrition-related disease. Food availability statistics based on food commodity production data are currently widely used as a proxy measure of national-level food consumption, but using data from the UK and Mexico we highlight the potential pitfalls of this approach. Despite limited resources for data collection, better systems of measurement are possible. Important drivers to improve collection systems may include efforts to meet international development goals and partnership with the private sector. A clearer understanding of the links between the agriculture and food system and population health will ensure that health becomes a critical driver of agricultural change.     

幼年竞争瓶颈对动力学行为的影响（英文）

通过建立具有非线性成熟率的食物网模型研究了幼年竞争瓶颈对种群动力学行为的影响,结论显示当竞争瓶颈比较弱的时,捕食者生活史中的幼年瓶颈对系统的影响要大于成年.模型存在两种可能的共存态或双稳定性,即消费者-捕食者和消费者平衡态共存,但是瓶颈不能诱导系统的双稳定性.进一步研究说明了选择不同的瓶颈或初始条件,瓶颈能够改变次级消费者对捕食者的净影响.     

The effect of food on microparasite transmission in the waterflea Daphnia magna

Studies on dynamics of trophic transmission usually refer to the predation of animals that contain parasites. Here, in contrast, I study the transmission of external stages of parasites namely of spores of the microsporidian gut parasites Glugoides intestinalis and Micro1. These spores are filter fed by the waterflea Daphnia magna and I was particularly interested in the effect of food on transmission success. It was hypothesized that food has a double impact on transmission success because of increased spore uptake on the one hand and increased spore defecation of infected waterfleas on the other. I tested for these assumed food effects in exposure experiments where transmission could occur naturally from infected to uninfected waterfleas in the presence or absence of food.
The major assumptions were confirmed. In one system transmission success was increased fourfold in the presence of food and feeding infected hosts had lower spore loads. The other system showed evidence for these effects. Feeding activity correlated positively with food in both systems and spore loads in infected waterfleas partially determined spore loads in exposed waterfleas.
I discuss the impact of food on infected and uninfected waterfleas in particular and on transmission success and epidemiology in general.     

Substance P in the central mechanism of the rabbit feeding response evoked by stimulation of the lateral hypothalamus

The effects of substance P on the central mechanisms of food motivation elicited by electrical stimulation of the lateral hypothalamus were studied in chronic experiments on rabbits. Intravenous injection of substance P (30 micrograms/kg) brought about a dramatic reduction in the excitability of the "food center" in the hypothalamus, which returned to normal 45-60 minutes after injection. Higher concentrations of substance P provoked food behavior inversion up to the replacement of food motivation by avoidance behavior. Intravenous injections of substance P disturbed the relationships between the hippocamp, midbrain reticular formation and hypothalamus seen in health. This manifested in complete cessation of the inhibitory effects of the dorsal hippocamp and facilitating influences of the midbrain reticular formation on the excitability of the hypothalamic "food center". It is assumed that disorders of the central mechanisms of food motivation may arise from the effects produced by substance P directly on the central nervous system or on the brain via changes in the hormonal balance and responses of the autonomous nervous system.     

Intralateral hypothalamic area injection of isoproterenol and propranolol affects food and water intake in broilers

The role played by adrenergic system in water intake, especially food intake, has long been known in mammals. In avian species, there have been many experiments exploring the effects of the adrenergic system in different sites in the central nervous system in meat- and egg-type poultry. This study was designed to examine the possible effects of intralateral hypothalamic area (ILHy) microinjections of a beta-adrenergic agonist, isoproterenol, and a beta-adrenoceptor blocker, propranolol, on food and water intake in 3-h food-deprived and 3-h water-deprived broiler cockerels. Our findings suggest that the β-adrenergic system directly affects food especially water intake in broilers. Although isoproterenol significantly (P ≤ 0.05) decreased food intake for the first 15 min, it reduced food intake during the experiment. Isoproterenol reduced water intake significantly (P ≤ 0.05), which was abolished by pretreatment with propranolol. It is proposed that β-adrenoceptors in LHy play a direct and indirect role in the regulation of food especially water intake in broiler cockerels.     

Organically Grown Food Provides Health Benefits to Drosophila melanogaster

The “organic food” market is the fastest growing food sector, yet it is unclear whether organically raised food is nutritionally superior to conventionally grown food and whether consuming organic food bestows health benefits. In order to evaluate potential health benefits of organic foods, we used the well-characterized fruit fly Drosophila melanogaster as a model system. Fruit flies were raised on a diets consisting of extracts of either conventionally or organically raised produce (bananas, potatoes, raisins, soy beans). Flies were then subjected to a variety of tests designed to assess overall fly health. Flies raised on diets made from organically grown produce had greater fertility and longevity. On certain food sources, greater activity and greater stress resistance was additionally observed, suggesting that organic food bestows positive effects on fly health. Our data show that Drosophila can be used as a convenient model system to experimentally test potential health effects of dietary components. Using this system, we provide evidence that organically raised food may provide animals with tangible benefits to overall health.