L14 Nutritional Assessment Flashcards
What is nutritional assesment?
What determines nutritional status?
A means of evaluating current nutritional status is part of the history and physical
Identifies the degree of deficiency and its probable cause
Nutrient stores determines nutritional status
What is the difference between macronutrients and micronutrients?
Macronutrients: energy source~lipids (depot fat), proteins, carbs
Micronutrients: iron, calcium, vitamins, minerals
Name two predictors of morbidity and mortality.
Quantity of lean body mass and adipose tissue
Why should you do a nutritional assesment?
- to make a diagnosis of either obesity or malnutrition
- to determine when to screen for disease
- to establish the adequacy of a diet
- to start developing a nutritional care plan
What makes up a nutritional assesment?
The ABCDs of Nutritional Assessment:
• Anthropometric measurements such as height and weight.
• Biochemical parameters are laboratory tests for compounds such as prealbumin, iron and vitamin B12
• Clinical evaluation
• Dietary history
What does adult height tell us?
How does adult height reflect environmental factors?
What are some environmental factors?
a glimpse into society’s well-being
variation mostly genetic
variation between populations is mostly environmental
Height reflects environmental factors that increase or decrease nutrition intake during growth (especially infancy, 6-8 yr old, adolescence)
Environmental factors: missing any of 45 essential nutrients, insufficient calories, iodine deficiency, illness
What does current body weight tell us?
What is the significance of serial weight measurements?
Current body weight is a measure of total body energy stores
Most useful when collected in serial fashion
Weight chage over time should be reported as percentage of one’s original weight
Unexplained weight loss of 10% or more maybe considered malnutrition
What is the single most significant measure of nutritional status?
Weight change
What is Ideal Body Weight (IBW)?
Varies with gender and height
Calculated using Hamwi formula, is a range of values
Male: 106lb +/- (6 lb for every inch above or below 5 ft) +/- 10%
Female: 100lb +/- 5 lb for every inch above or below 5 ft) +/- 10%
Underweight: <85% of IBW
Obese: >120% of IBW
What is the best and most commonly used index of obesity?
BMI
What is Body Mass Index (BMI)?
How is it calculated?
What is the advantage of using BMI?
What are the ranges for underweight, normal, overweight, and obese?
BMI = weight in kg x height in m^2
BMI = (weight in lb) / (height in inches^2 x 703)
One entity is used to evaluate body weight
Underweight: <18.5
Normal Weight: 18.5-24.9
Overweight: 25-29.9
Obese: > or equal to 30
*these values just for caucasians
What are the criteria for BMI cutoffs based on?
increasing risk of premature death
What are some disadvantages of using BMI?
- measures excess weight, not excess fat:(misleading for body-builders, etc) no relation between BMI and precent body fat- factors in with age as body fat increases and muscle mass increases but may have same BMI
- does not account for gender-women have 10% more body fat than men. for given BI, women have a decreased risk of premature mortality
- not universal- does not account for ethnicity. target BMI needed to trigger screening for hypertension, heart disease, and diabetes varies with ethnicity
What are two ways for assessing body fat?
Which is the gold standard?
What can we use body fat as a criteria for?
Hydrostatic weighing and DXA (dual energy x-ray absorptiometry)-gold standard, but expensive
Bioelectric impedance analysis (BIA): measures body water compartment using electric current. body fat has little water and is resistant to current, more fat = greater electrical resistance. Dehydration will results in over estimating percent body fat
Body fat is another criteria for evaluating obesity
What is the triceps skinfold thickness test?
used to estimate body fat as percentage of total weight
based on the fact that 50-80% of adipose tissue is subcutaneous
calipers are used to measure skin folds, multiple sites better
easy, rapid, inexpensive, but variable
Why is fat distribution important?
It is not just amount of body fat but the fat distribution that determines disease risk associated with obesity
Central or apple-shaped people carry fat above waist- associated with 2-fold greater risk of hypertension, hyperinsulinemia, diabetes, CV disease
How is fat distribution gender dependent?
Where does testosterone favor fat deposition?
Non-obese men: fat evenly distributed
Non-obese women: more fat in gluteofemoral area
Women with lower-body obesity (pear-shaped) have to weight about 20 lbs more than comparable men with upper-body obesity to show same health risks
Testosterone favors fat deposition in abdomen
What are ways to asses central or abdominal obesity?
Central obesity has more of what type of fat than lower-body obesity?
Waist circumference (WC)
Waist-to-hip ratio: fat accumulated on hips is cardioprotective. High risk for men = >1. High risk for women > or equal to 0.86
Central obesity has more visceral fat than lower-body obesity
What is the best predictor for risk of CVD and premature death?
Waist circumference is more closely associated to the risk of CVD and premature death than BMI or Waist-hip ratio
Male: WC greater than or equal to 40 = visceral obesity
Female: WC greater than or equal to 35 = visceral obesity
Men WC of 34 inches has 70% increased risk of DM
WC of greater or equal to 40 inches has 280% increased risk of DM
What is A Body Shape Index (ABSI)?
Why is the ABSI helpful?
Combines WC and BMI, but is independent of these factors
ABSI = WC/ (BMI)^2/3 x (height)^1/2
ABSI is helpful because BMI does not deal with fat distribution and normal BMI can mask metabolic abnormalities
25% of people with normal BMI are metabolically unhealthy (skinny fat)
50% of overweight people are metabolically healthy
elevated BMI does not necessarily reflect poor metabolic health
What is the most dangerous kind of fat?
Abdominal fat over subcutaneous fat
What are the two compartments of body protein?
What is used to assess wasting or malnutrition?
What is a marker of malnutrition in the elderly?
Somatic protein (skeletal muscle): muscle strength
Visceral protein: prealbumin and albumin
Mid upper arm circumferance (MUAC) assesses wasting or malnutrition. Children 6 months-5 years: <12.5cm = moderate acute malnutrition. <11cm = severe acute malnutrition
Calf circumference (CC) is marker of malnutrition in elderly. measured at point of greatest circumference. cc less than or equal to 30.5cm suggests protein energy malnutrition
What are biochemical markers?
What are visceral proteins?
Estimate the quantity of specific nutrient stores
eg. protein, iron, vit C, calcium
Prealbumin is used as measure of visceral or organ protein status. useful for screening patients at risk for malnutrition
How do you measure thiamin deficiency?
measure erythrocyte transketolase activity with and without added thiamin.
if added thiamin results in more than 25% increase in enzymatic activity, thiamin is deficient
How is the clinical assessment tailored to specific populations and used to identify individuals that have deficiencies or are at risk for nutrient deficiency?
Inner city children: lead exposure
Pregnant women: calcium intake
Elderly: malnutrition (nursing home v. in community)
What is a Mini Nutritional Assessment (MNA)?
Ranking of nutritional status based on many many factors.
Good = 24-30 MNA score
Risk of malnutrition = 17-23.5
Malnutrition < 17
What are the causative factors associated with malnutrition in the elderly?
MEALS ON WHEELS
Medication effects
Emotional problems
Anorexia nervosa or alcoholism
Late life paranoia
Swallowing disorders
Oral factors: dentures, etc
No money
Wandering, dementia behaviors
Hyperthyroidism, hypothyroidism
Enteric problems
Eating problems
Low salt, low cholesterol diet
Social problems
What are the most common procedures used to determine dietary history?
What are the disadvantages of these methods?
Plate diagram: hoard food
24-hour recall: forget snacks
1-3 day record: change of food choices, inaccurate estimates of quantity
food frequency questionnaires: can underestimate usual intakes
