- Количество слайдов: 37
UNIT 3 BASIC NUTRITIONAL GROUPS & NUTRITION THROUGHOUT THE LIFE CYCLE
Specific Objectives: At the end of this unit, students will be able to: 1) Know the importance of dividing nutrition into groups. 2) Identify the nutritional alternatives. 3) Identify the factors affecting choosing nutrition. 4) Discuss the nutritional needs of adult, children, pregnant, lactating mothers and the old age. •
Basic Nutritional Groups Importance of dividing nutrition into groups We have to take into our consideration the following: 1. Consider the age, sex, weight, developmental stage, the health status and the type of work of the individual or the group is engaged in. 2. Every day should be considered as one unit. 3. The diet plan should be adequate, in other word it should : – Supply all energy requirements, protein, minerals, vitamins and water. – Adequate according to the needs of the individual. – Digestible. – Free from infection and poisonous chemicals.
In planning diets whether through the quantitative or qualitative method we must consider: 1. Needs for growth and development. 2. Needs for type of work and mode of life. 3. Needs during infection. 4. Inter relationship of nutrients. •
• (A)Needs for growth and development: The nutritional needs for young healthy children are great as would be expected from the rapid rate of growth, in particular, the requirements for protein calories and iron are much greater proportionally in young children than adults, so a 70 kg man needs about 70 mg of protein daily in comparison a child of 12 kg needs about 25 gm of protein daily. .
(B) Needs according to the type of work and mode of life: Workers engaged in sedentary works require different diets than those, who are involved in heavy activities; The later need diets rich in calories and thiamin; workers working in a hot environments which will involve much sweating, water and salt intake should be stressed. Since salt absorption is improved if glucose is present, workers should take some carbohydrate as well as salt and water. For these purpose 0. 2% salt solution can be drunk or used with sweetened lemonades.
(C)Needs during infection: In malnourished children, infection occurs easier, last a longer time and have much mortality rates. On the other hand, infections play an important role in the initiation of malnutrition: many infections are characterized by poor appetite, vomiting and diarrhea. During infection there is a need for more calories. In fact, the basal energy requirements increases by 13% for every degree centigrade rise in temperature above normal; it has been known that in almost all febrile infections there is an increase in the excretion of nitrogen in urine, nitrogen loss may begin during the prodromal stage before the appearance of fever and clinical symptoms and may continue long after the fever subside.
(D)Inter relationship of nutrients: The body needs for different nutrients are related to one another, e. g. the requirements for the vitamin thiamin increases in the intake of carbohydrate.
I - The quantitative method of diet planning: 1. Determine first the daily caloric requirement. Basal metabolism. This the metabolism of the body when it is in the state of rest 4 hours after the food intake; it is constant per square meter/hour. It can also be assessed using the weight of the individual. It is one caloric/kg body weight/hour. There are various factors that can affect the basal metabolism: These includes sex, weight, height, skin area, age as well as pathological conditions as thyrotoxicosis and febrile condition.
Total metabolism: Equal to basal metabolism activities carried out by the individual. Example: Type of activity - rest in bed. - limited activities. - light activities - moderate activities - heavy activities % increases in the metabolism 10% 30% 50% 75% 100%
(2) Calculate the amount of protein needed by the subject, and then find out the calories given by these proteins; if for example a person takes one gm of protein/kg of his body weight and he has a weight of 65 kg, then he will need 65 gm of proteins then will yield 65 multiplying by 4 = 260 calories (where 1 gm of protein gives 4 calories). 3)All the recommended allowances of minerals and vitamins should be supplied and part of the protein should come from animal kingdom. •
II- The qualitative method: A)Group 1: Body building foods: meat, fish, eggs, milk and cheese. These groups provide protein, niacin, thiamin, riboflavin and iron. B) Group II: The bone building foods: milk and cheese, also cod liver oil; these groups provides calcium. They also supply high biological protein and riboflavin: these group of foods is needed highly for growing children and pregnant and lactating women.
(C) Group III: The vitality foods: Fruits and vegetables, provides vitamins especially C and A and mineral especially iron. (D) Group IV: Energy giving foods: Fats as butter, cream, oils. Cereals as bread, macaroni, rice and cakes, jams, and honey. These groups provides mainly energy workers involved in heavy activities and athletes require more of the energy group.
Children Nutrition: A) Bite size pieces of food which can be easily picked up with finger or spoon by the young child be provided. 1 -Such foods as raw carrots should be avoided until they can be chewed well and there is no danger of aspiration. 2 -Food should be saved in small portions so as not to overwhelm the child.
B) During the second year of life, growth rate to decelerates, calorie requirements drop, and children demonstrate marked disinterest in food, children should not be forced to eat: if they refuse, the food be removed without comment, and offered again at the next meal. C) A child should be encourages to food himself as soon as he is ready to manipulate a cup and spoon. D) It is helpful to feed children with the family.
NUTRITION IN PREGNANCY Calorie and protein allowances: During pregnancy, the mother's diet must provide the necessary nutrients for the maternal and fetal tissue formed during gestation. . These requirements are highest during the third trimester of pregnancy when the fetal growth rate is maximal: Recommended daily allowances for pregnancy are 30 kcal and 30 g of protein above the allowances for the non pregnant female. Recommended weight gain during pregnant female is 11 kg or more.
The following points are important to consider: (1) Lower weight gain are associated with lower birth weight. (2) Limiting weight gain during pregnancy is indicated in obese females. (3) Weight loss is not recommended even for obese female. (4) Excess weight gain does not cause pre-eclampsia.
Edema and sodium intake: Edema is a normal feature of pregnancy and is associated with higher birth weight, excessive weight gain as a result of edema is alarming because it could be a sign of pre-eclampsia, edema alone is not an indicator for salt restriction or administration of diuretics. Complications of diuretics therapy include electrolyte imbalance, hyperglycemia and pancreatitis in the mother and hyponatraemia and thrombocytopenia in the infants, thus in a normal pregnancy sodium restriction is not indicated and the use of diuretics is not indicated.
Mineral allowances: A decrease in hemoglobin concentration accompanying pregnancy is due in part to dilution; adequate iron supplementation will limit the decrease. 0. 5 gm of iron is required for maternal erythropoiesis during pregnancy. 0. 3 gm of iron is needed by the fetus thus 0. 8 gm of iron is needed during the second half of pregnancy. Because of increased absorption and decreased excretion of calcium in pregnancy as little as 300 mg/day may sufficient, calcium supplementation is recommended for women who do not drink milk.
Vitamin allowances: In normal pregnancy folate (folic acid) turnover is increased in rapidly growing maternal and fetal tissue, supplement with 200 -400 mg/day is recommended. In spite of its importance in calcium absorption, Vitamin D is not increased during pregnancy and lactation because an excess of the vitamin may promote neonatal hypercalcaemia. Plasma levels or urinary excretion of riboflavin, thiamin and vitamin A, C and B 12 are low during pregnancy. This situation is due to dilution and not due to depletion. Since supplementation does not correct the abnormalities. Supplementation, therefore is not normally required of particular importance, is the fact that an excessive intake of vitamin A may be teratogenic.
Nutritional aspect of lactation Recommend dietary allowances: (A) An optimal diet for lactation women furnishes somewhat more of each nutrient with the exception of vitamin D, than the amount recommended for non pregnant female. (B) Increase are given for energy intake (an additional 500 kcal/day) and protein (an additional 20 g/day. (C) Food sources, the increased energy and protein needs of lactation scan be met by drinking less than 1/4 of milk daily, this will not, however, provide the increased amounts of ascorbic acid, vitamin D and folic acid recommended, but this can be taken by adding fruits, vegetables oils.
(D) Generally, these are not needed except in situation in which intake of one or more nutrients is deficient, women who do not drink sufficient milk may need calcium supplements. (E) Some physicians advice supplements of iron, fluoride and vitamin D for breast feed infants.
Nutrition in the adolescent: • Adolescence is the period of life between the childhood and adulthood, characterized by a rapid increase in the rate of physical growth and changes involving psychological development. The age at onset range from 9. 5 -13. 5 years. Adequate nutrition is necessary to provide the energy and essential nutrients required for increased linear growth, increase nutrition due to accelerated growth and development.
Growth, sexual maturation and development during adolescence: A. Changes which occur during adolescence include an increase in the size of every organ except lymphoid tissue. • Muscle mass increase in both sexes, but the increase in the size of male. • Fat tissues in female during the entire period, but in males after an initial increase, there is a marked decrease after 16 years of age.
B. The chronology of sexual development varies significantly but the sequence is constant. - Girls: breast enlargement + menarche +weight gain. - Boys: testicular enlargement + increase in height and weight.
Nutritional requirements: (A) Basic nutrients: 1 - The requirements for calories, protein carbohydrate and fat are best expressed in terms of growth rate and state of physiologic development. 2 - To estimate calorie needs, physical activity must consider. a. Healthy males (11 -14) require 400 calories more per day than do female of this age group, due to increased activity. b. Girls have a peak calorie needs at menarche of 2400 calories followed by a slow decline to 2100 by age old 16.
c. Males consume 2400 calories at age 10, followed by increase to 3000 calories by age 16. 3 -Protein intake is in direct proportion to needs for other nutrients and should provide 12 -15% of the total calorie intake. 4 - Carbohydrate should supply 40 -50% calorie intake. 5 - Fats should constitute 30 -45% of calorie intake.
(B) Calcium requirements: - With marked bone growth, calcium needs increase paralleling to increased in calorie intake. - In both males and females, the calcium intake increases from 800 mg at 10 years of age to 1200 mg during growth. The primary source of calcium is milk product.
(C) Iron requirements: The need for iron is markedly increased during adolescence in both males and females. Environmental and psychological influences on diet: a- There is a poor eating habits results in nutritional deficiencies. b- The after school activities need more energy. c- The decline of family meals, eaten together has been an advice factor in adolescent nutrition. d-The teenage tends to buy inexpensive foods.
Nutritional Needs for Adult Nutrient needs change for both men and women in the middle-adult years. Energy needs decline based on loss of muscle mass and low physical activity. Waist circumference is increase by nearly 1 cm per year over these age range and beyond. Calcium intakes assume special importance, particularly for women. Menopause and the loss of estrogens bring about a decrease in calcium and absorption and an increase in bone turnover with a net loss of bone mass and increased risk of bone fracture.
Dietary Guidelines for Adults 1)Reduce total fat 30% or less calories and saturated fat to less than 10% of calories dietary cholesterol to less than 300 mg/day. 2) Eat five or more servings of vegetables or fruits daily. 3) Maintain moderate protein intake, not more than twice the RDA. 4) Balance food intake and physical activity appropriate body weight.
5) If you drink alcohol, limit it to no more than two standard drinks a day. 6) Limit total salt intake to 6 gms a day sodium chloride. 7) Maintain adequate calcium intake. 8) Avoid eating nutrient supplements with dose above RDA. 9) Maintain an optimal intake of fluoride.
Nutritional Needs for Old Age These categories were established to recognize the physiological changes and chronic diseases that continue to develop as we age and influence our nutritional needs.
1) Energy: The energy allowance for older adults takes into consideration age-related changes in muscle and active tissue and expected levels of physical activity. A physically active 65 year old man weighing 77 kg needs about 2600 kcal/day, and a physically active of this age weighing 57 kg needs about 2100 kcal/day.
2) Protein: The RDA for protein is the same for all adult ages 25 and older. A level of 0. 8 g/kg body weight is recommended for both genders with reference intake of 56 g/day for men and 46 g/day for women. Health status influences protein needs.
3) Minerals: Calcium rises from 1000 mg to 1200 mg for persons over age 50 as a strategy to reduce bone loss, bone fracture, and the development of osteoporosis.
4) Vitamins: Vitamin needs are unchanged from middle to older age, except for vitamin B 6 and vitamin D. Vitamin B 6 is used less efficiently by the older adult. , so the RDA is higher. Vitamin B 6 is stored and metabolized mainly in muscle, so muscle loss in older age may change the body's handling of this nutrient.