肥胖的營養(yǎng)治療

1、-作者xxxx-日期xxxx肥胖的營養(yǎng)治療【精品文檔】第十三章代謝性疾病營養(yǎng)治療第一節(jié)肥胖癥 Obesity is defined as an excess body fat content for stature. Ideally, the best assessment of obesity would be a measure of actual body fat. Among adults, the body mass index (BMI, expressed as kg/m2) has been recommended internationally as a measu

2、re of obesity. A BMI between 25.0 and 29.9 defines overweight (24.0 to 27.9 for Chinese); a BMI 30 defines obesity (28 for Chinese). Unlike adult, no universal definition of the weight-for-height measures necessary to define obesity in youth exists, but definitions have been proposed. WHO expert com

3、mittee recommended that for infants and children a childs weight for height be compared with mean age- and sex-specific values in the National Center for Health Statistics (NCHS) and WHO reference data. Children with a weight-for-height value >2 standard deviation scores (Z score) above the media

4、n are classified as overweight. For adolescents the committee recommended BMI as the best indicator; however, age and sex must still be considered. Adolescents whose age- and sex-specific BMI is 85th percentile BMI of a reference population are classified as at risk for overweight.Obesity can be vie

5、wed as both a disease and a risk factor for chronic disease and other morbidities. Increased fat in the abdominal region predicts physiological risk factors for cardiovascular disease (CVD), independent of body mass. Among adults, both ratio of waist circumference to hip circumference and the waist

6、circumference alone have been used to assess body fat distribution. Waist-to hip ratios >1.0 for men and >0.85 for women have been used to identify people at increased risk for morbidity. For both adults and children, obesity is associated with a higher prevalence of risk factors for cardiovas

7、cular disease and type 2 diabetes. People with overweight or obesity are more likely than normal-weight people to experience elevated blood pressure; dyslipidemias, such as high levels of total cholesterol, triglycerides, and LDL and low levels of HDL; and insulin resistance. They are also more like

8、ly to experience 2 or more these risk factors.Ultimately, overweight and obesity are caused by a chronic imbalance between energy intake and energy expenditure. Two behaviors are thought to contribute to energy imbalance; excessive energy intake and inadequate physical activity. Genetics also contri

9、bute significantly to obesity. Ultimately, any intervention to facilitate weight loss or prevent weight gain must result in an appropriate relation between energy expenditure and energy intake within the individuals: to facilitate weight loss, expenditure must exceed intake; to prevent weight gain,

10、expenditure must equal energy intake. 6.28MJ800-1500 kcal/d) can reduce body weight by an average of 8% over 3-12 months. Increased physical activity may aid weight loss by increasing energy expenditure and by helping maintain lean body mass and thus resting metabolic rate. Increased physical a

11、ctivity contributes modestly to weight loss for both adults and children, but the effect of physical activity alone is generally smaller than that of energy reduction. Physical activity does appear to be important in long-term weight maintenance. 一、概述肥胖癥（obesity）是指體內(nèi)儲存過多的脂肪。表現(xiàn)為脂肪細(xì)胞體積增大和（或）脂肪細(xì)胞數(shù)增多。正常

12、成年男子的脂肪組織約占體重的15%20%，女子占20%25%。若成年男子脂肪組織超過20%25%，女子超過30%，即為肥胖。常表現(xiàn)為體重超過相應(yīng)身高體重標(biāo)準(zhǔn)值的20%以上。按病因和發(fā)病機(jī)制，肥胖癥可分為單純性肥胖（simple obesity）和繼發(fā)性肥胖兩大類。前者是遺傳因素和環(huán)境因素共同作用的結(jié)果，是一種慢性代謝異常疾病，它常與高血壓、高脂血癥、冠心病、2型糖尿病等集結(jié)出現(xiàn)或是這些疾病的重要危險(xiǎn)因素。隨著生活水平的改善和體力勞動(dòng)的減少，肥胖癥有逐年增加的趨勢，已成為世界性的健康問題之一。繼發(fā)性肥胖癥是某些疾?。ㄈ缂谞钕俟δ軠p退癥、性功能減退癥、下丘腦-垂體炎癥、腫瘤、庫欣綜合征等）的臨床表

13、現(xiàn)之一。本節(jié)主要討論單純性肥胖。肥胖癥的判斷主要是根據(jù)理想體重和體質(zhì)指數(shù)， 輕度肥胖癥者無癥狀，中重度肥胖癥者因體重負(fù)荷增大，可出現(xiàn)氣急、關(guān)節(jié)痛、肌肉酸痛、體力活動(dòng)減少等。通常男性肥胖患者脂肪主要分布在腰部以上，集中在腹部，稱為男性型、蘋果型肥胖，俗稱“將軍肚”；女性肥胖患者脂肪主要分布在腰部以下，如下腹部、臀、大腿，稱為女性型、梨型肥胖。蘋果型比梨型肥胖患者更易發(fā)生代謝綜合征。公司白領(lǐng)、公務(wù)員、財(cái)務(wù)人員為主，他們每天靜坐時(shí)間長，普遍缺乏主動(dòng)鍛煉，最易肥胖?；颊叱Ｒ蝮w型而有自卑感、焦慮、內(nèi)向、抑郁、孤獨(dú)等心理問題，此外，肥胖患者可伴發(fā)高血壓、高脂血癥、糖尿病、膽石癥、膽囊炎等。二、營養(yǎng)代謝特點(diǎn)

14、（一）能量長期能量攝入大于能量消耗量，多余的能量，不管來自哪一類能源物質(zhì)（脂肪、碳水化合物或蛋白質(zhì)）均可轉(zhuǎn)變成脂肪儲存在體內(nèi)，過量的體脂儲備即可引起肥胖。攝入過多能量可發(fā)生在任何年齡，但在幼年開始多食對肥胖的發(fā)生具有重要意義。成年起病者多為脂肪細(xì)胞體積增大，而幼年起病者多為脂肪細(xì)胞數(shù)量增多和體積增大，更不易控制。體力活動(dòng)不足引起的能量消耗下降可能是肥胖的一個(gè)原因，也可能是肥胖的后果，因?yàn)榉逝植∪顺Ｊ艿匠靶?，自卑感?qiáng)，逐漸形成內(nèi)向抑郁，不愿活動(dòng)，因而耗能減少，形成惡性循環(huán)。因此，應(yīng)控制能量攝入和增加能量消耗，才能糾正能量代謝的失衡。 （二）脂肪和碳水化合物膳食脂肪的能量密度高，過多攝入易使能量超

15、標(biāo)，且易發(fā)生酮癥。飽和脂肪酸易轉(zhuǎn)化為體脂，引起肥胖。有學(xué)者認(rèn)為，機(jī)體有一控制系統(tǒng)調(diào)節(jié)體脂含量固定在某一水平，稱為調(diào)定點(diǎn)（set point）。肥胖癥的調(diào)定點(diǎn)較高，因而難以減重，或減重后難以維持。單、雙糖消化吸收快，易使機(jī)體遭受多糖的沖擊性負(fù)荷，而反饋性胰島素過度分泌，后者促進(jìn)葡萄糖進(jìn)入細(xì)胞合成體脂。 （三）蛋白質(zhì)肥胖病人由于限制膳食能量攝入量，會引起機(jī)體組織蛋白分解，易發(fā)生蛋白質(zhì)營養(yǎng)不良，故應(yīng)提高低能量膳食中蛋白質(zhì)，尤其是優(yōu)質(zhì)蛋白質(zhì)的比例。但蛋白質(zhì)攝入過量，含氮代謝產(chǎn)物增加，會加重肝腎負(fù)擔(dān)。 三、營養(yǎng)治療原則（一）營養(yǎng)治療的目的肥胖是一種慢性病，因長期能量攝入超過能量消耗所引起。因此，應(yīng)持之以

16、恒，長期堅(jiān)持控制能量攝入，和增加體能消耗，促進(jìn)體脂分解，切不可急于求成。預(yù)防肥胖比治療容易且更有意義。營養(yǎng)治療的目的是通過長期攝入低能量的平衡膳食，結(jié)合增加運(yùn)動(dòng)，借以消耗體脂，從而減輕體重，同時(shí)又能維持身心健康。 （二）營養(yǎng)治療原則1. 限制總能量攝入量 能量供給量應(yīng)低于能量消耗量。成年輕度肥胖癥，以比平日減少能量攝入125250kcal（）/d來配制一日三餐的膳食；中重度肥胖癥，減少5001000kal（）/d，但每人能量攝入量不應(yīng)少于1000 kcal（）/d，這是較長時(shí)間能堅(jiān)持的最低水平。減少能量攝入量應(yīng)循序漸進(jìn)，切忌驟然降至最低水平以下。體重也不宜驟減，一般以每月減重為宜。2. 限制脂

17、肪攝入 脂肪應(yīng)占總能量的20%25%，不宜超過30%；膳食膽固醇供給量以少于300mg/d為宜。飲食中以控制肉、蛋、全脂乳等動(dòng)物性脂肪為主，烹調(diào)用油控制在1020g/d，宜用植物油，以便提供脂溶性維生素和必需脂肪酸。食物宜以蒸、煮、燉、拌、鹵等少油烹調(diào)方法制備為主，以減少用油量。3. 適當(dāng)減少碳水化合物攝入 膳食碳水化合物占總能量45%60%為宜，過低易產(chǎn)生酮癥，過高會影響蛋白質(zhì)的攝入量。應(yīng)以復(fù)合碳水化合物為主，如谷類，盡量少用或不用富含精制糖的食品，如甜的糕點(diǎn)。主食一般控制在150250g/d。4. 蛋白質(zhì)供給要滿足需要 低能量膳食主要是控制脂肪和碳水化合物攝入量，而蛋白質(zhì)供給應(yīng)充足，否則不

18、利于健康。但過多蛋白質(zhì)也不利于減重。一般蛋白質(zhì)占總能量的20%30%為宜，每公斤理想體重1g/d以上，其中至少有50%為優(yōu)質(zhì)蛋白質(zhì)，來自肉、蛋、奶和豆制品。5. 充足的維生素、無機(jī)鹽和膳食纖維 膳食除通過調(diào)整三大宏量營養(yǎng)素來限制能量攝入量外，其它營養(yǎng)素，包括各種無機(jī)鹽和維生素應(yīng)供給充足，且比例要均衡。新鮮蔬菜和水果是無機(jī)鹽和維生素的重要來源，且富含膳食纖維和水分，屬低能量食物，有充饑作用，故應(yīng)多選用。必要時(shí)可適量補(bǔ)充維生素和無機(jī)鹽制劑，以防缺乏。因肥胖常伴高血壓等，為了減少水在體內(nèi)潴留，應(yīng)限制食鹽攝入量，每人不宜超過6g/d。6. 養(yǎng)成良好的飲食習(xí)慣和積極運(yùn)動(dòng) 宜一日三餐、定時(shí)定量，晚餐不應(yīng)吃得過多過飽；少吃零食、甜食和含糖飲料；吃飯應(yīng)細(xì)嚼慢咽，可延長用餐時(shí)間，這樣即使食量少也可達(dá)到飽腹感；可先吃些低能量的蔬菜類食物，借以充饑，然后再吃主食；酒不利于脂肪和糖代謝，應(yīng)盡量少飲。積極并堅(jiān)持運(yùn)動(dòng)，既可增加能量消耗，減少體脂，又可保持肌肉組織強(qiáng)健。因此，調(diào)節(jié)膳食減少能量攝入量和配合運(yùn)動(dòng)增加能量消耗，雙管齊下是減肥的最佳方法。四、食物選擇（一）宜用食物谷類、各種瘦肉、魚、豆、奶、蛋類均可選擇，但應(yīng)限量。蔬菜和水果可多選用。 （二）忌（少）用的食物