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Nutrition
Titles Nutrition: definition Water: Water intake and out put Caloric requirements Energy Contents of Food Basal Metabolic Rate Energy requirementObjectives: Principles of nutrition to be the basis for more detailed information of nutrition and to understand diseases related to nutrition.
Nutrition Nutrition is the science that deals with the relationship of food with the functioning living organism. The nutritional requirements of a person are 3 folds: 1. Water. 2. Calories and 3. Specific molecules (Vitamins, minerals and oxygen).
WATER:Water is more essential to life than is food, for a person may live weeks without food but only days without water. It is an essential component of blood, lymph, the secretions of the body and every cell in the body. More than Ѕ the adult’s weight is water (60% for men and 54% for women) The extra cellular compartment account for 1/3 of body water including plasma and interstitial spaces, while the intracellular fluid contains 2/3 of body water.Fluid is necessary for the functioning of every organ in the body. It is a structural component of cells, when a cell loses their water they lose their shape. It is the universal medium in which the various chemical reactions of the body take place.
As a carrier it aid in digestion, absorption, circulation and excretion. It is essential in the regulation of body temperature. It plays an important part in mechanical functions, such as the lubrication of joints and the movement of the viscera in the abdominal cavity. Waste products from the tissues are transferred to the blood in a watery solution, they are carried by the blood which is about 80% water and they are excreted via the kidneys in urine (about 97% water).
The same water is reused many times and for different purposes. Approximately 8 L of digestive juice are produced and secreted by the glands in 24 h. Over 4L of water are always circulating in the blood stream. It is estimated that some 50 L of water cross the cell membranes in a day. In the kidney large volumes of water (180L) carry the dissolved waste materials through the capsule of the nephrones, most of the water, with some of its useful dissolved materials is reabsorbed (99%). The urine, which is excreted, is the concentrated aqueous solution of the waste products.
Water intake and output: Normally the body losses water through 4 routes; 1. From the skin. 2.From the lung (Total about 800 ml) 3.From the kidneys (1-1.5L) and 4.From the intestine (about 200 ml). Large amount of water are also lost in abnormal conditions including; fever, vomiting, burns and hemorrhage. Fluids are replaced by the ingestion of liquids and foods containing water. Although some water is formed within the body as an end product of food metabolism. From 1-1.5 L of water or other liquids should be consumed daily in order to insure a sufficient amount of water for body functions.
Energy requirement:
Physical Activity:
Body Size:
Age:
Climate and Environment:
Growth and body size of childhood and adolescence:
Pregnancy:
Lactation:
Objectives: 1. To understand the body requirements in normal condition and in certain other conditions 2. To study the importance of carbohydrate as a source of energy and the special uses and benefits of fibers in the diet
Basal Metabolic Rate: When a subject is at complete rest and no physical work is being carried out energy is required for the activity of the internal organs and to maintain the body temperature constant. This energy is called the basal metabolic rate or Resting metabolism. The BMR is determined experimentally when the subject is lying down at complete physical and mental rest, wearing light clothing, in a room comfortably worm and at least 12 h after the last meal. Energy requirement: There is a wide variation in the energy requirements of individuals, even of those having the same occupations and apparently living similar kind of lives. The energy requirements of individual are dependent on four variables:
Table showing different requirements of different activity of peoples: Sedentary Moderately Active Very Active At sleep 500 500 500 At work 900 1200 1800 Non-Occupational 1300 1300 1300 Activity ______ _______ _______ 2700 Kcal 3000 Kcal 3600 Kcal Example of sedentary occupations includes office workers, drivers, teachers, journalists, doctors, lowers, students, and so on. Examples of moderately active occupations include industry and railway workers, postmen, farm workers and so on. Examples of very active occupations include steel workers, builders and so on.
Body Size: A tall man weighing 100 kg obviously needs more food than a short man weighing 50 kg. There are many researches showing the relationship between body requirement of energy and body weight and indicating that the big man require more calories than a small man. Age: Age affect energy requirements into 2 ways:
As people become older they tend to work in employment which requires a smaller expenditure of energy and they reduce their physical exercise. The BMR per unite of body weight decreases slowly after the early twenties. This decline with age is largely due to a reduction in the proportion of metabolically active tissues in the body. Climate and Environment: It is a common opinion that cold weather stimulates appetite and hot weather depresses it. Any effect of climate is mainly due to changes in physical activity, but also the BMR is some 10% lower in tropics than in temperate climates.
Growth and body size of childhood and adolescence: The energy intake of children of different ages must obviously allow for satisfactory growth and physical development and for the high degree of activity characteristic of healthy children. The energy requirement per kg of child body weight is more than double that of adult during the first year of life but falls slowly as the rate of growth per unit of body weight falls with age.
Pregnancy: During pregnancy extra energy is needed for the growth of fetus and the placenta. Additional energy is also required for movements and activities when the mother becomes heavier. Lactation: The quantity of breast milk produced by individual women varies widely. However an additional dietary intake of about 500 Kcal/day during lactation is required, although it is normal for a woman to lay down about 4 kg of fat during pregnancy and this provides a reserve for use in lactation.
Carbohydrate in diet: Fiber in the diet:
Protein in the diet:Protein requirements:
Protein allowance:
Protein Deficiency:
Secondary protein deficiency or conditioned may arise as a result of pathological process as follows:
Objective: To understand the constituents of each type food and its importance in nutrition, and To understand complications of protein deficiency.
Carbohydrate in diet: Carbohydrates are a major source of energy in the human diet; each gram of carbohydrate provides approximately 4 Kcal. Although fat and protein can replaces carbohydrate as a source of energy, however some carbohydrates are essential for humans. Brain, nerve and lung tissues require glucose as their source of energy. During hypoglycemia and when the brain deprived of glucose convulsion may result. Carbohydrates especially sugars are converted to triglyceride in the liver and become available to cell for energy or stored in the adipose tissues. Also during transamination reaction intermediary products of carbohydrate metabolism can be converted into amino acids and used for protein synthesis.
It has also been indicated that the reduction of fiber in the diet may be a factor in the increased incidence of cancer of the colon. New researches has indicated an important function of fiber and that it delay hydrolysis of starchy food so give chance to insulin to released so decreasing the incidence of diabetes. Protein in the diet: The nutritive value of protein depends on the proportion of the essential amino acids in its molecule, although all amino acids are required for building of new tissues. Protein is divided into animal and vegetable proteins. Animal proteins are more important than vegetables as they contain larger amount of essential amino acids.
Protein requirements: Protein requirements can be either; 1. The requirement for the essential amino acids and 2. Requirement for the total protein; which must be available to the body for the synthesis of non-essential amino acids. Protein allowance: It has been recommended a daily intake of 0.8 g of protein/kg of body weight for adults. Hence the recommendation for a 70-kg male is 56 g of protein. An additional amount of protein to allow for growth has been included in the allowance for children in the age group from 1-18 years. An additional 30 g / day has also been added for pregnancy from the second month to the end of gestation, 20 additional grams is recommended during lactation to cover the milk produced. It is highly desirable that at least 1/3 of the daily protein intake be derived from animal sources. It is also necessary that some good quality proteins be included in every meal.
Protein Deficiency: If the dietary protein supply is insufficient, the cells lack amino acids for their synthetic activities. The effect of this is clear in young child as growth slows down or even stops. The effect of protein deficiency is also on organs and tissues of adults. The first tissue affected by protein deficiency is the mucosa of the intestines and the glands, which secrete the digestive enzymes, in consequence a failure to digest and absorb the food leading to diarrhea and loss of water and electrolytes. Also failure of the liver to maintained its normal structure and functions. In addition fat accumulates in the liver cells, the liver also fails to synthesis plasma albumin and this is liable to lead to edema. Later, protein deficiency leads to a failure to maintain the structure of skeletal muscles and the production of RBCs so muscle wasting and anemia results.
Analysis of plasma proteins is frequently used as an index of protein deficiency. Total proteins 68 58-78 g/LAlbumin 43 35-56 g/LGlobulin 22 16-31 g/LFibrinogen 3 2-4 g/LA plasma albumin concentration below 35 g/L means protein deficiency and in sever deficiency states the level often falls to 15 g/L and some times lower. The concentration of γ- globulin is often raised owing to the presence of infections. A low plasma albumin and a high plasma globulin are frequently found together where the people are poor with inadequate diet.
Secondary protein deficiency or conditioned may arise as a result of pathological process as follows: Utilization of protein as a source of energy, owing to an inadequate supply of carbohydrate and fat. Loss of protein in the urine as a result of diseases of the kidneys. Loss of protein from the body by other routes such as hemorrhage or wounds. Failure to absorb protein in various disorders of the intestine. Failure of a damaged liver to synthesize protein particularly albumin from amino acids absorbed from the intestines. Damage to tissues (Trauma) e.g. injuries, burns, fractured bones or surgical operations are followed by a period of negative nitrogen balance. (More tissue protein is catabolic than the diets can immediately replace).
Fat in the diet:
Malnutrition:Protein- Energy (Protein-calorie) malnutrition (PEM or PCM);
Marasmus:
Kwashiorkor:
Objectives: To complete the informations of the types of nutritional components of the diet concerning fats To understand the effects of deficiency of calories and protein on human health specially the infants and children and diseases related to that including Marasmus and Kwashiorkor
Fat in the diet: The amount of fats in the diets varies greatly. In many rich countries fats usually contributes 35-45% of the total energy, whereas in poor countries the figure is 15% or even lower. Since there is evidence of increased susceptibility to coronary heart diseases among individuals with elevated levels of cholesterol &/or TG; attention is focused on those food constituents which appear to affect the level of these 2 substances (these are the total fat and sugar intake and the proportion of saturated to polyunsaturated fatty acids and cholesterol). However it is advisable to use diet-giving energy from fat of about 20%.
This is especially important if the person has reached middle age and it is important to remember that it is healthier to substitute animal fat with vegetable oils in the prevention and treatment of atherosclerosis. Anyhow a high fat intake is necessary for very active people spending over 4000 Kcal/day. On the other hand complex carbohydrate rather than Simple sugars should replace the fat in the diet when weight reduction is required in order to reduce serum TG levels. So the foods selected will need to include more cereals grain, legumes, vegetables, fish and vegetable oils and less animal fat and sugar.
Malnutrition: Estimates indicated that there is a billion and half human in the world today suffering from severe, moderate,or mild malnutrition. Some children will die from malnutrition; larger number will suffer physical and possibly mental retardation and will be more susceptible to infectious diseases.
Death rates in these children may be 20-50 times the rate in rich communities in Europe and America. Marasmus: Marasmus is more likely to develop in children under one year of age when breast feeding fails or not continued for sufficient period of time, followed by dirty artificial feeding with very dilute milk or milk products given in inadequate amount thus the diet is low in both energy and proteins.
The infant with Marasmus is more than 40% below standard body weight. There is no subcutaneous fat, muscle wasting and diminution of length is usually clear. Edema is not noticeable . The GIT is also affected and so watery diarrhea and bulky acid stool may be found and if infective gastroenteritis is added the diarrhea is severe. In addition the skin and mucous membrane are dry and atrophic. The Marasmic infant looks like a little old man with a big head and huge eyes, wrinkled face and tiny body. Such infants are particularly susceptible to infectious diseases and their mortality is high.
Kwashiorkor:The name is African means the disease the older baby gets when the next one is born. In this case the presence of edema is clear. It is due to severe protein deficiency but in which energy intake may be adequate. Kwashiorkor is an acute condition of short duration in which recovery or death occurs relatively rapidly. The mortality rate even among hospitalized children is high. The first and essential sign is the failure of growth. The child’s skin shows dermatitis consists of areas of pigmentation and other areas of depigmentation. Ulcers occur over pressure points and deep cracks in skin folds.
The GIT is also affected and so watery diarrhea and large semisolid acid stool is shown. The muscles are usually wasted as a result many children regress in their physical development. Anemia is usually present and may be severe. Some children have tremors resemble to Parkinsonism. Treatment: Specific therapy consists in providing the child with sufficient amount of protein and energy and in controlling infection. Milk is excellent for this purpose. Many children can not tolerate whole milk, as diarrhea is increase (due to the presence of fat).
So they are treated with skimmed milk. Another problem with milk is its lactose content, as when the GIT is seriously damaged is unable to produce lactase; this result in fermentation of lactose by bacteria of the bowel and so diarrhea may increase. In this condition a casein preparation must be used in addition to glucose as a source of energy and few quantities of salt is also added. Fortunately the digestive power improves rapidly with high protein intake.
Weight Control:
Obesity:Causes:
Prevention:
Treatment:
Objectives: To understand the problems when weight is not controlled specially in rich countries, communities or persons resulting in obesity. To understand obesity its complications , causes and treatment
Weight Control: Weight control is very important during life to prevent health problems associated with obesity. It has been observed that Diabetes Mellitus and hypertension occur more frequently in obese individuals whose blood levels of triglycerides and cholesterol are usually elevated. Obesity: It is defined as the state in which an excess of fat accumulates in the body. The proportion of fat in the total body weight gives a scientific measure of obesity. Mean values of body fat for normal young men are about 12% and for young women are about 26%.
A man regarded obese when the amount of fat increase more than 20% of his total weight and a woman is considered obese if her fat increase to more than 30% than the total body weight. Obesity may be in both sexes but it is usually more common in women, it is specially occur after pregnancy and at the menopause. Now a days obesity index (Body mass index) is used on a large scale as an index of obesity or over weight. Weight (kg) Obesity Index (BMI)= Length in (m)2
The typical result of this division range between 20-25. When the result is between 25-30 the subject has overweight, While when above than 30 it is obesity. However, result less than 20 means underweight specially if less than 18
Causes: Increased caloric intake, which exceeds the energy needs of the body. Change in living habits: As the habits in many countries have developed from that of 50 years ago e.g. work hours have been shortened, transportation is easier, the homes are well heated. Emotional problems: Many people who are overweight eat because they have nothing else to do. They may eat more when they are under stress or when they feel unappreciated.
4. Activity: As obese person is less active than his counterpart of the same age, this inactivity lower the caloric need of the body and in this way contribute to overweight. 5. Endocrine: In small percentage of overweight individuals, the obesity may be due to disturbances of functions of the endocrine glands such as thyroid and pituitary.
Prevention: Usually obesity starts in childhood and continues and increases in adult, so early measures are indicated for the prevention of obesity. One have to chick his weight in a suitable periods of time and when an increase of weight is noted one have to limit or decrease some of the unnecessary food such as sugars, cream, butter and others. Also it is important to decrease food for every body at the late twenties and foreword. At the same time an increase in the exercise such as walking and sports is necessary.
Treatment: By Food Control: Since adipose tissues are stores for excess energy, then the calorie intake must be below the actual daily needs and so one think to reduce the quantity of diet taken to less than the actual need. Since carbohydrates and fats constitute the greatest source of calories in the diet so they must be reduced, some prefer to reduce fat to minimum and keeping normal amount of carbohydrate while others prefer the reduction of both fats and carbohydrates equally.
By excise: Exercise is required and it is very necessary to decrease weight or to burn the energy. One should follow a regular exercise or at least increase walking or swimming or other sports. By drugs: Amphetamine and its derivatives: They depress the appetite and stimulate metabolism and help to burn the excess fat. However it has many side effects. b. Thyroxin: It stimulates metabolism. This help in decreasing weight. However it is contra indicated except in those rare cases of obesity associated with evidence of hypothyroidism.
c. Methyl Cellulose: This is indigestible substance add bulk to the diet it is a harmless substance. d. Fenfluramin hydrochloride (Ponderax): It decreases the felling of hunger in addition it helps in metabolizing food and burns fats. e. Mazindol (Teronac): It is another drug for the treatment of obesity and it has similar effects to Ponderax but has fewer side effects than Ponderax. f. Orlistat (Xenical): It is the latest drug used for the treatment of obesity. It is a specific and reversible inhibiter of gastrointestinal lipases. Thus lipase become unable to hydrolyze dietary fat in the form of TG
Underweight: Weight more than 10% lower than ideal is usually considered to be abnormal especially in persons less than 25 years and is usually require medical investigation. Under weight may be due to an inadequate energy intake or to excessive body activity or it may be familial. Diseases such as malignancy, G.I.T. disorders, chronic infectious diseases or endocrine disturbances such as hyperthyroidism may be causes of progressive weight loss. Under weight due to an inadequate caloric intake may be a serious condition especially in the young as resistance to infections particularly to TB may be lowered . Also the occurrence of the complications of pregnancy in young women may result from malnutrition due to an inadequate energy intake.
Kilo calories/100 g or ml
ProductsMilk and its products
67
Whole milk الحليب الكامل 37
Skimmed milk بدون دسم 95
Buffalo Milk حايب الجمس 50
Yoghurt اللبن 310
Cheddar cheese جبن شيدار 334
Light cream الكريم 575
Heavy cream القيمر 722
Butter الزبده 867
Cooking fats and oils الدهون
Kilo calories/100 g or ml
ProductsMeat
153
Lamb لحم الغنم 138
Beef لحم البقر 133
Chicken الدجاج 200
Liver الكبد 110
Fish السمك 167
Eggs البيض Cereals
279
Bread الخبز 362
Burgel البرغل 364
Rice الرز 370
Chick peas الحمص 358
Peas البزاليا
Kilo calories/100 g or ml
Products
Vegetables
69
Beans الباقلاء 84
Potatoes البطاطس 48
Carrot الجزر 28
Lettuce الخس 26
Spinach السبانخ 24
Marraow الشجر))القرع 19
Tomatoes الطماطم 22
Green Pepperالفلفل الأخضر Fruits
41
Orange البرتقال 46
Lemon الليمون 74
Apple التفاح 63
White grippe العنب الأبيض 76
Black grippeالعنب الأسود 370
Date التمر