Nutritional requirement of vulnerable groups
د- هديل فاضل فرهود
1- Pregnant women
2- Lactating women
3- Infants; growing children&adolescents
4- Geriatric age groups (male & female over 65 years old)
Nutritional requirement during pregnancy Many physiological, biochemical & hormonal change during pregnancy that affect the need of various nutrients.
These physiological changes include:
1- Increase blood volume (50%), decrease Hb, decrease serum albumin & water soluble vitamins.
2- Increase fat soluble vitamins, cholesterol, phospholipids & free fatty acids.
3- Increase cardiac output & pulse rate.
4- Increase maternal O2 requirement & decrease threshold for CO2.
5- Nausea, vomiting, change of appetite & heart burn.
6- Decrease GI motility lead to constipation.
7- Increase GFR & greater amount of amino acid, glucose & water soluble vit appear in urine.
8- Increase in BMR by 20% during pregnancy.
9- Decrease in secretion of HCl acid in the stomach which may affect the absorption of iron & calcium.
10- The pregnant women secrets over 30 hormones that help to control and integrate all the physiological changes involved in pregnancy.
Maternal diet & nutritional status are important factors influencing the course & outcome of pregnancy.
The nutrients present in maternal blood reach the fetal blood stream via the placenta.
Four major mechanisms are used for maternal-fetal transfer of nutrients:
@ Passive diffusion (e.g. O2, CO2, fatty acids, steroids, nucleosides, electrolytes &fat-soluble vit).
@facilitated diffusion (e.g. sugars).
@active transport (e.g. amino acids, some cat ions, & water-soluble vit).
@endocytosis (e.g. proteins)
Maternal malnutrition in humans interferes with normal placental growth as reflected by a lower weight & smaller placental size & delivered of a full-term low birth weight (LBW) infant, also called small for date, small for gestational age, fetal growth retarded, or intra uterine growth retardation.
LBW is associated with increased mortality & morbidity including higher incidence of congenital abnormalities & poor post natal growth.
Nutritional needs of pregnant women are affected by:
Age, parity, pre-pregnancy nutritional status, intervals between pregnancies, general medical & obstetric condition.
Weight gain during pregnancy:
Optimum wt gain depends on pre-pregnancy nutritional status.
@ Under wt women (BMI < 18.5): 12-16 Kg
@ Normal wt women (BMI 18.5-25): 11-14 kg
@ Over wt women (BMI ? 25): 9-10 Kg
@ The recommended target wt gain range for women carrying twin is 16-20.5 kg.
Normal wt women usually gain 3.5 kg by the end of the 1st 20 weeks of pregnancy. It is recommended that women of normal pre-pregnancy wt gain 0.4 kg per week in the 2nd & 3rd trimester of pregnancy, while the wt gain for under wt or over wt women in these trimester are 0.5 & 0.3 kg/wk respectively.
Unusual pattern of wt gain should attract our attention like e.g. sharp increase in wt gain after 20 wk of gestation especially if it is associated with blood pressure elevation & protein urea (pre-eclampsia).
Component of wt gain during pregnancy:
Fetus 25-27% placenta 5%
Amniotic fluid 6% expansion of blood volume 11%
Growth of uterus & breast 11% increase extra-cellular fluid 13%
Increase maternal fat stores 25-27%
Wt gain in 1st trimester mainly from growth of maternal tissue. In 2nd trimester, wt gain in maternal & fetal tissues. In 3rd trimester, most of the wt gain from growth of fetal tissues.
Poor wt gain could be due to:
1- Inadequate intake.
2- Chronic & ongoing nausea.
3- Adequate intake but output losses
4- Increased metabolic demands beyond the normal aspects of pregnancy
5- High energy expenditure
Nutrient requirements
1. Energy: calories are the single most important nutritional factor in determining birth weight .
an average of about an extra 150-200 cal/day are recommended during the 1st trimester & 350 cal/day thereafter with average of an additional 300 cal/day for pregnant women.
2- protein :
The fetal/placental unit consumes approximately 1 kg of protein during pregnancy, with the majority of this requirement in the last six months. To fulfill this need, the gravida should ingest 1.1 g/kg/day protein, which is moderately higher than the 0.8 g/kg/day recommended for non pregnant adult women
3- Carbohydrates: a minimum of 50-200 g/day of digestible carbohydrates should be provided.
4- Fat & essential fatty acids: dietary fat is important in fetal & early infant growth because this is the period of organogenesis, where there is a high demand of EFA for the synthesis of cell structural lipid. The approximate accumulation of EFA during pregnancy is estimated to be about 620 g which include the demand for uterine, placenta, mammary glands & fetal growth & the increased maternal blood volume.
To meet these needs, 4.5 % of the expected caloric intake in the form of EFA is recommended during pregnancy.
5- Minerals:
@calcium: 1200 mg is recommended during pregnancy.
@iron: IDA is common problem among pregnancy.
Requirement in non-pregnant (absorbed Fe) ==2.4 mg/day
Requirement in pregnant (absorbed Fe) ==
1st trim=0.8mg/day
2nd trim=4.4mg/day
3rd trim=6.3mg/d
Women with iron deficiency anemia (first or third trimester hemoglobin (Hb) <11 g/dL or second trimester Hb ? 10.4 g/dL and low serum ferritin) should receive an additional iron supplement of 30 to 120 mg per day until the anemia is corrected ay
@Zinc: is an essential growth factor, deficiency cause increase rate of malformation & poor pregnant outcome.
Female over 10 years of age required 12mg of zinc/day, in pregnancy additional 3-5mg is recommended. Food sources of zinc are oysters, meat , poultry ,eggs & sea food , cereal , legumes .
@Vitamins: adequate supplies of vit during pregnancy are necessary to ensure normal fetal development.
Folic acid — Folate requirements are higher in pregnancy. The RDA recommendation is for all fertile women to take at least 400 micrograms of folic acid per day, increasing to 600 micrograms per day in pregnancy. The preconceptional period is the optimal time for ensuring adequate folic acid consumption
Nutrition during lactation
The mother needs a well-balanced diet to produce sufficient milk to satisfy her infant s. The special diet in lactation should have the following properties:
A- energy: extra 500 cal/day (about 90 calories are required for production of 100ml of milk).
B- protein: about 12 g of extra protein are needed per day (mother s milk contains approximately 1g protein per 100 ml).
C- calcium: 1200 mg daily is essential.
D- Essential fatty acids: about 3-5 g/day of EFA are secreted in milk, additional 1-2 % of energy in the form of EFA is recommended in 1st three months of lactation & an additional 2-4% of energy above the basic requirement is recommended thereafter.
E- Water-soluble vit: the vitamins content of human milk is depend upon the mother s current vit intake & her vit stores.
Because most water-soluble vit are not stored, the mother s diet should contain adequate amount of these nutrients.
Nutritional requirements during infancy
The infants need for all nutrients is more than for adult because of relatively high metabolic rate & special needs for growth & maturation.
1- energy: the recommended requirement is about 120 cal/kg BW per day during the 1st 6 months of life. After 6 month the energy requirement gradually decreases to approximately 105 cal/kg/day.
2- Protein: is required for maintains, growth & maturation of tissue. The protein requirement is 2-2.5 g/kg/day during the 1st year.
3- Carbohydrates: the major CHO source in early infancy is lactose (present in breast milk) & is the preferred sugar because it also enhances the absorption of dietary calcium & magnesium by lowering PH of the intestinal content.
The ability to hydrolyze maltose, sucrose & lactose is adequate in newborn infants. Amylase which is essential for digestion of starch is very low during the first 4-6 month of age. Therefore, foods containing starch are avoided during the 1st few months. About half of the dairy calories can be in the form of CHO.
4- Lipids: fat play a role in the absorption of fat-soluble vit & is a source of essential fatty acids which is important factor in brain growth & development. The calories in the fat are needed during infancy.
5- Vitamins & minerals: adequate intake of vit & minerals are required for normal growth & development.
Vitamin K appears to be concern only in the newborn infant, routinely administered 0.5-1mg IM or 1mg orally to protect them against hemorrhagic diseases. This dose lasts until the infant s intestinal bacteria are established & begin to synthesize the vit.
If the infant is exclusively breast feed by a healthy, well nourished mother & if it has adequate exposure to sun light, then no vit supplementation is necessary after the 1st 6 months.
If the exposure to sun light is limited, infant should receive 10 mg (400 IU) of vit D supplementation daily.
Iron stores present at birth can last up to 6 month of age.
Fluoride is important in the preeruptive as well as the developing phase of tooth growth, may be a necessary supplement (0.25mg daily) in the infant diet.
6- water: the infant is susceptible to a lack of water because the obligatory water loss through the kidney & skin is greater than in the adult.
Under ordinary circumstances, human milk & properly prepared infant formulas supply sufficient water.
Breast feeding during infancy
Human milk is superior to any other kind of animal milk or formula & is the perfect food for the growth of human infant.
The benefits of human milk are related to its special biochemical, immunological & psychological attributes.
1- Biochemical benefits:
The milk that is produced during the first few days after delivery is called colostrum which is higher in protein & low in fat. It also contains a number of substances which render the infant less susceptible to certain infections such as gastroenteritis.
Colostrum causes the newborn infant s intestine to grow in size to be ready to receive an increased volume of food.
Beginning the 3rd & 4th day after delivery, a slow transition occur from colostrum to milk production which contain a little more fat & lactose & less protein & salt concentration.
The infant formula cannot possibly duplicate this gradual change in milk composition which continues for about 2-3 weeks, by the end of this period the composition of milk is stable.
It has 1% protein (as opposed to 3-4% in cow s milk).
The protein when partly digested separates into two fractions:
Curd casein (about 30%) & the remainder is whey which is soluble.
In cow s milk only 2% is whey & 80% is casein.
@the casein of human milk is rich in cystein while that from cow s milk is low in these amino acids.
@ Taurine is found in human milk in high amount & absent in cow s milk.
@ ?-lactoglobulin is dominant whey protein in human milk, ?-lactoglobulin is the major whey protein in cow s milk.
?-lactoglobulin is most common food allergen in infancy.
@CHO: the predominant CHO of milk is lactose & is present in high amount (6.8g/dl) in human milk, 4.8 g in cow s milk.
@ Fat: the content of fat in human milk is about 3.8% (about the same as cow s milk) & provides 40-50% of the energy.
@bile salt-stimulated lipase: in human milk which helps digestion of fat. Nearly all human milk fat is digested & absorbed & very little is lost in the stool.
2- Immunological benefits:
Human milk contain substances neutralize, destroy & eliminate viruses, bacteria & parasites which are known to cause enteritis, colitis & some other diseases. Four of these substances are:
A- Secretary immunoglobulin A(S-IgA): it is a whey protein & is resistance to the action of digestive enzyme. The concentration of S-IgA is very high in colostrum & decreases in mature milk, although it s absolute amount remains high throughout lactation even one year post partum.
B- lactoferrin: is part of the whey fraction of milk protein. It has an extremely high affinity for iron, even greater than transferring, & thus making iron unavailable for growth of certain iron-dependant bacteria in the gastrointestinal tract (Escherichia coli). Lactoferrin is present in human milk but not in cow s milk.
C- Lysozyme: is an enzyme present in whey protein & has antimicrobial action. It s concentration in human milk is about 300 times more than in cow s milk.
D- Bifidus factor: is a specific factor that promotes the growth of Lactobacillus bifidus. This factor is present in human milk but not in cow s milk.
L. bifidus inhibits the growth of potential pathogens such as E. coli.
3- Psychological aspects:
Breast feeding provides special relationship & closeness that accompanies nursing.
It is readily available at the proper temperature & needs no time for preparation. It is fresh & free of contaminating bacteria & contains bacterial & viral antibodies.
Its allergic reaction is minimal.
The digestibility of human milk also confers an advantage for breast fed-infant over cow s milk.
@@ Comparison Between Human & Cow s milk @@
Constituent human milk cow s milk
Biochemical
Total protein 1% 3.5%
Curd protein 0.30% 2.8%
Whey protein 0.77% 0.75%
Cystein increase decrease
Taurine increase decrease
Lactose 6.8g/dl 4.8g/dl
Fat 3.8% 3.8%
Poly unsaturated fatty acids ++++ +
Bile salt-stimulated lipase ++++ -
Immunological
S-IgA(whey protein) ++++ -
Lactoferrin (whey protein) ++++ _
Lysozyme (whey protein) high (300 higher) decrease
Bifidus factor ++++ _
Solid Foods During Infancy
For the past few decades there has been a trend towards earlier introduction of solid foods, often after 4-6 weeks of life.
The current recommendation is to delay it until 4-6 months of age.
Starch digestion is not efficient during the early period of infancy, but improves as the infant grows. After 6 months breast feeding can continue, but the energy needs of the infant may exceed those which can be met by breast-feeding.
The addition of semisolid food is therefore described. This can also provide iron & other nutrients.
The first solid foods to be given are usually iron-fortified cereals. It is important not to introduce mixed foods until each component has been given separately for about a week, for if an allergy or intolerance develops it will be difficult to identify the offending food component.
Rice is the best cereal to begin with because it is least likely to cause allergies.
Strained fruits & vegetables are added next.
Towards the end of the first year, transition to family foods & self-feeding occurs.
Nutrition during childhood
The time from one year of age until puberty is often referred to as "latent" period of growth, because the children are growing & developing bones, teeth, muscle & blood, they need more nutritious food in proportion to their wt. than do adult.
Prior to adolescence there is little difference in yearly height increment between the sexes. As a result, differences in nutritional requirement for male & female have not been established for children less than 11 year of age.
The daily energy &protein intake for children:
Calories protein (g)
Age (years) total per Kg BW total per Kg
1-3 1300 102 16 1.2
4-6 1800 90 24 1.1
7-10 2000 70 28 1.0
Nutrition during adolescence
Adolescence is the period between the onset of puberty & adulthood (i.e. 10-20 years of age).
Puberty is an intensely anabolic period with increases in height & weight, alterations in body composition resulting from increased lean body mass, & changes in the quantity & distribution of fat.
A rapid growth spurt begins in most girls between the age of 10-13 years old & in most boys between the ages 12 to 15 years, this growth spurt lasts about three years.
A- Energy & protein: caloric & protein requirement increase with metabolic demands of growth as follow:
Daily energy & protein intake for adolescent
Calories protein
Age (years) total per kg BW total per kg BW
Boys 11-14 2500 55 45 0.28
15-18 3000 45 59 0.33
19-24 2900 40 58 0.33
Girls 11-14 2200 47 46 0.29
15-18 2200 40 44 0.26
19-24 2200 38 46 0.28
B- Vitamins & minerals: like other nutrients they are all needed in increased amounts in proportion to energy requirement.
@calcium: is required for normal skeletal growth the need increase from 800 mg to 1200 mg/day.
@iron: 18mg/day for adolescence of both sexes.
@zinc: is necessary for growth & sexual maturity & retention of this nutrient increases significantly during the growth spurt. The richest sources of zinc are meat, seafood, eggs & milk.
Obesity
Lec
د- هديل فاضل فرهود
Obesity is becoming a global epidemic in both children & adults. It occurs in individuals when body fat is very high relative to lean body mass & is defined as body mass index (BMI) ? 30 kg/m2.
Absolute prevalence of obesity varies among countries (0.7-78.5). However, large rises in prevalence have been observed across the globe over the past few decades.
Overweight & obesity affect almost 2/3 (65.1%) of US adult.
The WHO estimates that over a billion adults are overweight & over 300 million are obese world wide. We are facing global obesity crises.
In USA, the prevalence of obesity in men, women & children is reported to be 28, 34 & 17% respectively.
It is a cause of major morbidity & mortality, is associated with numerous comorbidites such as cardiovascular diseases, type 2 diabetes, hypertension, sleep apnea/sleep disordered breathing, osteoarithritis as well as some cancers.
Obesity is associated with an increased risk of morbidity & mortality as well as reduced life expectancy, obesity responsible for more than 2.8 million deaths per year world wide.
@ Classification of obesity:
I- classification is based on number & size of adipose cell:
1- Hypertrophic obesity: many individuals, often those with mild or moderate obesity beginning in middle age, have an adipose tissue with normal number of adipocytes but containing large quantities of fat in each cell.
2- hyperplastic obesity: other individuals, often those with marked obesity & a history dating to early childhood, has an adipose depot made up of too many adipocytes each containing fat reasonably normal in quantity.
II- classification according to fat distribution:
1- Android, apple shaped or upper body obesity: is associated with increased risk of diabetes, hypertension & cardiovascular diseases, this type of obesity is most common in males.
2- Gynoid, pear shaped or lower body obesity: the fat distributed in the lower extremities around the hips or femoral region, is relatively benign & is common in females.
Note: a simple determination of waist to hip circumference can identify the two types of obesity (a ratio is about 0.7 is considered normal, > 0.7 upper body obesity, < 0.7 lower body obesity).
@ Causes of obesity:
A- Primary: genetics, twin studies indicate strong correlation in body weight & body fatness between identical twins & it appears that heredity plays a substantial role in the development of obesity in this case.
Family studies show that obesity runs in families, but they do not critically separate environmental from genetic factors.
B- secondary:
1- Excessive calories intake.
2- Inactivity.
3- Socioeconomic class: in the west, the low socio-economic class person is obese, while in the east, the high socio-economic class person is obese.
4- Endocrine disorder as myxoedema, Cushing syndrome.
@ Complications of obesity:
1- Diabetes: the prevalence of diabetes is about 2.9 times higher in overweight than in normal weight individuals (poor control of NIDDM)
2- Cerebrovascular: obesity is major risk factor to CVA.
3- Coronary heart disease: increase TG &/or cholesterol, high Bpr.
4- Respiratory complications as dyspnea.
5- Gout & arthritis.
6- Gall stones.
7- Cancer: ca. colon & prostate in males & of the breast in females.
8- Undesirable social, psychological & economic consequences of obesity.
@ Management of obesity:
A- History taking:
*history of chronic diseases
*was the wt gain over a short or long period of time.
*when did person start to complain of obesity.
*the appetite. *smoking habit
*psychological & social stress. *alcohol intake
*current drug therapy that affect the wt.
*risk factors such as angina, MI, stroke
*family history of obesity, eating behavior *number of meals per day.
*type of snakes
*ask about symptoms of hypothyroidism e.g. lethargy, slow speech.
*the symptoms of any diseases suspected to cause of secondary obesity.
B- Examination:
*look for signs of disease causing secondary obesity, blood pressure…….
*waist/hip ratio, weight, height, skin fold thickness.
*mid-arm muscle circumference, head circumference.
*body mass index (BMI) = WT/ (HT) 2=Kg/m2
The degree of obesity is classified as follows:
@BMI of 20-24.9 ------ within the range.
@BMI of 25-29.9 ------ over wt, relative risk.
@BMI of 30-35 ------ grade I obesity.
@BMI of 35-40 ------ grade II obesity.
@BMI of > 40 ------ morbid obesity, high risk.
C- Investigations: depend on our suspicion (e.g. NIDDM, Cushing syndrome), lipid profile, TSH, blood glucose (random &fsting), urine analysis, gamaglutamite transferase for alcoholic liver disease.
D- Treatment:
1- If we identify a specific cause(s), we treat it accordingly.
2- life-style modification: life style approaches offer a combination of treatment strategies that focus on all aspects of wt loss (e.g. diet, physical activity). By it the individuals make gradual changes in diet & physical activity with the use of behavioral strategies.
The result is progressive reduction in wt over time. Usually, the goal of this approach is an initial wt loss of approximately 10% which is associated with a decrease in obesity-related health consequences.
A- Diet: is to follow a balanced mildly hypo caloric diet. An important consideration for any change in diet is that individuals make slow changes over the course of time.
B- Physical activity: more likely exercise decrease appetite than increasing it, increase resting metabolic rate, when exercise intake after meals the thermic effect of meal may be increase. (Loss 500 calories/day=lose one pound each week)
c- Behavior modification: are used to encourage positive change in diet & activity levels. The most commonly used behavioral strategies are:
Self-monitoring, goal setting, stimulus control, problem solving & cognitive restructuring.
3- Psychological support: the obese person should not be blamed for his obesity but should be supported & encouraged from his doctor, family & friends to continue exercise & modify his eating behavior.
4- appetite suppressant : the national institute for health & clinical excellence in UK recommended pharmacotherapy, in conjunction with lifestyle modification, for obese individuals (i.e. BMI of 30kg/m2) & for over wt person with BMI greater than 27kg/m2 accompanied by at least one co morbidity.
5- Surgery: (used in morbid obesity) surgical techniques involve either creating a small bowel to produce a malabsorption of ingested calories, or creating a smaller stomach.
Eating Disorders
Eating disorders refers to a heterogeneous group of conditions characterized by sever disturbance in eating behavior.
A-Anorexia Nervosa:
Is a clinical syndrome of self-induced starvation characterized by a voluntary refusal to eat due to an intense fear of fatness & disturbed perception of body size. It occurs 15-20 times more frequently in females than males.
Atypical patient with this disorder is a white-female from middle to upper middle class family. In more than half of cases the syndrome begins before age 20 & in about 3/4 it occurs before age 25 years.
It is a potentially life-threaten disorder characterized by the patient s refusal to maintain body wt above 85% of what would be expected based on age & height.
@Causes: the specific cause(s) of the disease is still not known, but both biological & psychological factors may be involved. There is increase risk of anorexia nervosa among siblings (6%) with a 4-5 fold differences in concordance rates for monozygotic twin. This suggests a predisposing role for genetic factors.
@ Clinical features:
In addition to the skeletal-like appearance, sever complication (including any of the consequences of starvation) are possible in this disorder.
Amenorrhea (occur in about 30%), osteoporosis, decrease in BMR, lowered heart rate, hypotension, hypothermia, decrease WBC, hypoproteinemia, & anemia.
@Management:
Anorexia nervosa is a chronic illness requiring a multidisciplinary management approach using medical, psychiatric, nutritional therapy.
Sever malnutrition is not only life-threatening, but it also impairs thinking so the psychological treatment is not possible until nutritional status is improved.
Modest steady wt gain is an adequate goal in the early phase of the treatment.
Long-term psychotherapy is usually indicated.
With nutrition & psychotherapy 2/3 of cases recover to normal.
B- Bulimia Nervosa:
Is defined as recurrent episodes of rapid uncontrollable ingestion of large amounts of food in a short period of time usually followed by purging, either by forced vomiting &/or abuse of laxatives or diuretics.
This eating disorder is a significant problem for about 8% of adolescents & young adult females.
They generally look healthy & their behavior is unnoticed by friends & family
The patients who seek help do so because of feelings of guilty, anxiety or depression & more aware by her behavior & may be more willing to accept treatment.
@ Causes:
Unknown, but biologically & psychological role may present.
@ Clinical features:
There are no clinical signs of bulimia. Medical complications are the consequence of vomiting & laxative abuse which reveals:
Salivary gland hypertrophy due to vomiting, the induction of vomiting & dental erosion due to prolonged & repeated exposure to an acidic environment.
Irregular menses is frequent, metabolic alkalosis, hypochloremia & hypokalemia, cardiac arrhythmias.
@ Treatment:
Normalizing the patient s eating patterns & to change the patient s attitude towards food, eating & body size. Psychological therapy may be needed.
C- Binge Eating:
Here the binge are not followed by purges as in bulimia nervosa, those affected usually become obese.
D- Baryphobia:
This occurs when children themselves & parents put their children on the same low caloric diet that they follow. Children do not get adequate calories for growth.
E- Pica:
Ingestion of unsuitable substances having little or no nutritional value. Pica of pregnancy is most often reported as consumption of dirt, laundry starch, or clay.