Factors affecting dietary patterns

1. health status

2. ability to chew, swallow, and drink

3. culture and religion

4. socioeconomic status

5. personal preference

6. psychological factors

7. alcohol and drugs

Energy needs

1. basal metabolism – energy required for ongoing internal processes such as heartbeat

2. basal metabolic rate (BMR) – influenced by gender, age, activity level, body composition

Proteins

1. complex organic compounds comprised of amino acids

2. body breaks protein down into 22 amino acids

3. all but eight amino acids are produced by the body

4. “complete protein” food contains the eight essential amino acids not produced by the body (most meat, fish, poultry and dairy products)

5. “incomplete protein” food lacks one or more of the eight amino acids (most vegetables and fruits)

6. incomplete proteins can be combined to yield a complete protein: for example, beans and rice

7. functions of protein

   1. secondary energy source (four kcal/gram)

   2. essential for cell growth

   3. efficiency can affect all of body - organs, tissues, skin, muscles

   4. recommended protein intake: 0.42 grams per 0.4 kg of body weight

   5. the body's only source of nitrogen

   6. negative nitrogen balance can occur with infection, burns, fever, starvation, and injury

Vitamins

1. organic substances essential for body growth and metabolism

2. found only in plants and animals; body cannot synthesize them; depends on dietary intake

3. types (according to their solvent)

   1. water soluble (B1, B2, B6, B12, C) 

      • cannot be stored in body; require daily intake

   2. fat soluble (A, D, E, K) 

      • can be stored in body

Minerals

1. inorganic substances essential as catalysts in biochemical reactions

2. form most inorganic material in the body

3. functions:

   1. catalyst for many body reactions such as regulation of acid-base balance

   2. help cells metabolize, tissues absorb nutrients, and heart muscle respond

   3. minerals work synergistically; a deficiency of one mineral can disturb the action of other minerals

   4. types - grouped according to amount found in body

      • major minerals - calcium, magnesium, sodium, potassium, phosphorus, sulfur, chlorine; function known 

      • trace minerals - iron, copper, iodine, manganese, cobalt, zinc and molybdenum; function unclear

      • another group of trace minerals; found in even smaller amounts; function unclear

Water

1. critical body component essential for cell function

2. accounts for 60 to 70% total body weight in adults; 70 to 75% children functions

3. provides normal turgor

4. regulates body temperature

5. dietary sources: liquids and solids, such as fresh fruits and vegetables

6. deficiency: severe deficiency leads to dehydration and death

7. fluid intake normally equals fluid output

Total volume of fluid and amount of electrolytes remain relatively constant in the body

Fluid balance and electrolyte balance is interdependent

Body balances fluid and electrolytes primarily by adjusting output, and secondarily by adjusting intake.

Fluid balance is also maintained by osmosis (illustration )

Major electrolytes

1. cations

   1. sodium - most abundant cation in extracellular fluid

      • regulates cell size via osmosis

      • essential in maintaining water balance, transmitting nerve impulses, and contracting muscles

      • regulates acid-base balance by exchanging hydrogen ions for sodium ions in kidney

      • normal lab value for serum sodium is 135 to 145 mEq/L

      • sodium is regulated by salt intake, aldosterone, and urinary output

      • sources include table salt, processed meats, snacks and canned food (illustration )

   2. potassium - most abundant cation of intracellular fluid

      • potassium pump draws potassium into cell

      • essential for polarization and repolarization of nerve and muscle fibers

      • regulates neuro muscular excitability and muscle contraction

      • sources include wholegrains, meat, legumes, fruits and vegetables

      • regulated by kidneys

      • normal lab value for serum potassium is 3.5 to 5.3 mEq/L

   3. calcium - essential for cell membrane integrity, cardiac contraction, healthy bones and teeth, and functioning of nerves and muscles

   4. magnesium - normal constituent of bone; cofactor for enzymes in energy metabolism, neurochemical activities, muscular excitability

2. anions

   1. chloride

      • most abundant anion in extracellular fluid

      • helps balance sodium

      • normal lab value for serum chloride is 100 to 106 mEq/L

Maintenance of fluid volume

1. osmoreceptor system

   1. balances fluid intake volume by the regulation of water output volume

   2. dehydration stimulates osmoreceptors which activate the thirst control center; person feels thirsty and seeks water

   3. also stimulates antidiuretic hormone (ADH) secretion which decreases urinary output by causing the reabsorption of water in the tubules

2. circulatory system

   1. increases in fluid intake increase circulatory volume

   2. this increased volume stimulates the kidney for an increased glomerular filtration rate

   3. end result is an increase in urine output to decrease the initial curculatory volume

3. thirst center

   1. located in hypothalamus

   2. stimulated by

      • increased plasma osmolality

      • angiotensin II

      • dry pharyngeal muscous membranes

      • decreased plasma volume

      • depleted potassium

      • psychological factors

Maintenance of electrolyte balance

1. aldosterone - hormone (mineralcorticoid)

   1. when extracellular fluid sodium decreases or potassium levels increase

   2. adrenal cortex secretes aldosterone

   3. kidneys stimulated by aldosterone to increase reabsorbtion of sodium and decreased reabsorbtion of potassium

   4. results in water reabsorption and increased blood volume

2. parathyroid

   1. parathyroid secretes parthyroid hormone (PTH), also called parathormone

   2. stimulates release of calcium from bone, reabsorbtion in small intestine and kidney tubules

   3. when serum calcium level is low, PTH secretion increases

   4. when serum calcium level rises, PTH secretion falls

   5. high levels of active vitamin D inhibit PTH and low levels or magnesium stimulate PTH secretion

Therapeutic nutrition

2. modification of the nutritional needs based on disease condition

3. considerations for administering therapeutic diets

   1. condition of client - physical, emotional, mental ability of client to tolerate diet

   2. willingness of client to comply with diet

4. types of therapeutic diets

   1. diabetic

      1. goal is maintenance of normal weight

      2. dietary ratio 5:2:1 (carbohydrates to fat to protein)

      3. level of activity determines energy requirements

      4. non-insulin dependent diabetes mellitus (NIDDM) can usually be controlled by diet therapy

      5. diet individualized according to client's age, build, weight, and activity level

      6. keeping a regular schedule of meals and snacks is essential

   2. low protein diet

      1. for renal disease such as pyelonephritis, uremia, kidney failure

      2. normal protein intake 40 to 60 gm/day

      3. restricted foods: meats and other foods high in protein such as legumes, fish, dairy

   3. high protein diet

      1. for conditions such as burns, anemia, malabsorbtion syndromes, ulcerative colitis

      2. include high quality proteins or protein supplements such as sustagen

   4. low calcium diet

      1. prevents formation of renal calculi

      2. limit 400 mg per day instead of normal 800 mg

      3. restricts dried fruits and vegetables, shell fish, cheese, nuts

   5. acid ash diet

      1. prevents stone formation

      2. restricts carbonated beverages, dried fruits, banana, figs, chocolate, nuts, olives, pickles

   6. low purine diet

      1. prevents uric acid stone; used with gout clients

      2. lowers levels of purine, the precursor of uric acid

      3. restricts glandular meats, gravies, fowl, fish, and high meat quantities

   7. low cholesterol

      1. used for cardiovascular disease, high serum cholesterol levels

      2. normal amount of cholesterol intake - 250 to 300 mg/day

      3. restricts eggs, beef, liver, lobster, ice cream

Nutritional assessment: evaluate

1. weight change

2. appetite

3. food intolerance

4. chewing and swallowing

5. indigestion

6. elimination habits

7. eating behaviors

8. nutrient-drug interacions

9. anthropometric measurements

Feeding tubes

1. indications-inability to ingest, chew, or swallow food, but GI tract intact

2. tube inserted through nose into stomach or small bowel; or inserted endoscopically; gastrostomy tube or PEG tube, jejunostomy tube

3. types of tubes and feedings

   1. small bore feeding tube: 8 to 12 Fr and 36 to 43 inches long

      • difficult to aspirate stomach contents

      • may be impossible to auscultate an air bolus; or air bolus may be heard even when tube is not in stomach

      • tubes may become displaced even when securely taped

      • hard to verify placement; best method is by xray

   2. enteral tube feedings

      • keep head of bed raised, to prevent aspiration

      • assess placement of tube

      • inject ten ml air into nasogastric tube (ng tube) and listen with stethoscope for rush of air over stomach

        • aspirate gastric contents and check if pH is acidic

        • radiologic confirmation

      • administer enteral feeding

        • continuous

        • to prevent bacterial growth, do not hang tube feeding for longer than eight hours

      • assess gastric residual

        • every four hours if continuous feeding or

        • before you begin intermittent feedings

   3. tube feeding formulas

      • Vivonex, Isocal, Portagen, etc.

   4. complications

      • aspiration

      • gastrointestinal complications (diarrhea)

      • electrolyte or metabolic problems

Nutritional supplements/liquids

1. dehydration/diarrhea:

   1. infants: Infalyte, Pedialyte, Ricelyte

   2. older children: sports electrolyte replacement drinks

   3. infant formulas: standard and high-calorie

   4. specialty formulas:

      • predigested (e.g. Pregestamil, Nutramigen)

      • high-calorie supplements (Scandishakes, Carnation instant breakfasts)

Parenteral nutrition: see Lesson 6 of this course

Measures to improve nutrition intake of client

1. frequent small feedings

2. feeding assistance

3. offering preferred foods

4. ethnic foods
5. PART 2