完整版)营养与食品卫生学重点

完整版)营养与食品卫生学重点

绪论

营养学是一门研究人体营养规律及其改善措施的科学。营养则是指人体摄取、消化、吸收和利用食物中营养物质以满足机体生理需要的生物学过程。《皇帝内经素问》中指出：“五谷为养，五果为助，五畜为益，五菜为充，气味合而服之，以补精益气”。现代营养学分为三个时期：营养学的萌芽与形成期（1785--1945年）；营养学的全面发展与成熟期（1945--1985年）；营养学发展的突破与孕育期（1985年--）。

第一章营养学基础

营养素（nutrient）是指食物中可给人体提供能量、机体构成成分和组织修复以及生理调节功能的化学成分。营养素包括六大类：水、脂肪、糖类、蛋白质、矿物质、维生素。人体组成成分中，碳、氢、氧、氮占比超过96%；细胞内液ICF 占比2/3，外液ECF占比1/3；骨密度（BMD）和血液体积均为5L。

蛋白质（protein）是营养素的一种。必需氨基酸是指人体

不能合成或合成速度不能满足机体需要，必须从食物中直接获得的氨基酸，共有8种加上组氨酸（婴儿）。条件必需氨基酸则是指半胱氨酸和酪氨酸，它们不能被人体充分合成。氨基酸模式则是指蛋白质中各种必需氨基酸的构成比例，其中色氨酸的比例为1.完全蛋白质是指种类齐全，模式接近的蛋白质，可维持成人健康，也可促进儿童生长发育。限制氨基酸是指食物蛋白质中一种或几种必需氨基酸相对含量较低，导致其它氨基酸在体内不能被充分利用而浪费造成其营养价值降低。蛋白质互补作用则是指不同食物间相互补充必需氨基酸不足的作用。

蛋白质的功能包括构成机体组织、构成特殊生理活性物质以及供能。在人体内，小肠是蛋白质吸收的主要场所。氨基酸池是指存在于人体各组织、器官和体液中的游离氨基酸。氨基酸转运子分为两类：钠依赖型和非钠依赖型。必要的氮损失（ONL）是指机体媒体由于皮肤、毛发和黏膜的脱落，妇女

的月经失血及肠道菌体死亡排出的约20g以上的蛋白质的损失。氮平衡是指蛋白质的摄入量与排出量之间的关系，包括零氮平

衡、正氮平衡和负氮平衡。蛋白质的营养价值评价包括蛋白质的含量、消化率和利用率。

availability (BV) XXX to which food protein is XXX.

BV = XXX nitrogen x 100

Protein efficiency。(PER) is the average weight gain per gram of protein XXX.

Amino acid score (AAS) and protein digestibility-corrected amino acid score (PDCAAS) are used to XXX.

Protein-XXX (PEM) in adults has a mended nutrient intake (RNI) of 1.16 g/(kg·d) and should account for 10%-12% of total energy.

Lipids include XXX.

Triglycerides play several roles in the body。including energy storage and n (1 g of fat can produce 39.7 kJ of energy)。

maintenance of normal body temperature。n of organs from external forces。endocrine n。XXX carbohydrates。protein-sparing effects。XXX。they increase satiety。improve sensory properties。and provide fat-XXX.

Fatty acids are classified based on their carbon chain length (long-chain。medium-chain。and short-chain) and degree of n (saturated。monounsaturated。and polyunsaturated)。The most common XXX oleic acidXXX and alpha-linolenic acid。They can also be XXX (cis or trans).

XXX (EFA) XXX from food。They include the n-6 series of linoleic acid and the n-3 series of alpha-linolenic acid。eicosapentaenoic acid (EPA)。and docosahexaenoic acid (DHA).

Phospholipids provide XXX。form logical membranes。act as XXX industry。lower blood cholesterol。prevent atherosclerosis。prevent fatty liver。XXX。XXX。Sterols。XXX。XXX.

The XXX dietary fat includes its digestibility。essential fatty acid content。n of us fatty acids。content of fat-soluble vitamins。and other XXX as DHA。EPA。and arachidonic acid。The mended intake of fat for adults is 20%-30% of total energy。and the intake of EFA should be at least 3% of total energy.

XXX (D-type。which is the only type utilized by the human body)。fructose。and galactose。as well as disaccharides such as sucrose。lactose。maltose。XXX.

Carbohydrates can be classified into different types based on the number of XXXsaccharides。for example。are composed of

3-10 XXX。XXX raffinose。XXX and are known as the "soybean flatulence factor." On the other hand。polysaccharides are composed of more than 10 XXX.

Polysaccharides XXX into different types based on their structure and n。Starch。for example。can be absorbed by the body and is XXX。on the other hand。cannot be digested by the body。Fiber。which includes both XXX。is also a type of polysaccharide.