Lecture 9 Flashcards
Nutritional Status
balance between nutrient intake and expenditure (health condition)
Measures of nutritional status reflect intake, absorption, metabolism, storage and excretion
Assessments of Nutritional Status
- Individual level: diagnosis, screening, intervention and monitoring
- Population level: policy setting, programme evaluation, nutritional surveillance
Integration of Nutrition into routine clinical case
-consultation or assesment has limited time- gp or hospital
1. Past medical history/Family history (ask about related nutritional issues)
2. Medications, OTC/supplements/herbs (70% takes OTC/non-pharmacteuical supplement, some do interact with drugs. therefore if prescribe medication need to know it wont interact)
3. Diet/social/Lifestyle history (family support, have children)
4. Review of systems
5. Physical examination
6. Laboratory evaluation (blood tests etc)
Final Result: 7. Assessment and plan
ABCD(E) of nutrition assessment
Anthropometric (physical examination) Biochemical (blood tests) Clinical (general) Dietary (diet) Economical/Social
Anthropometric
Changes in physical dimensions (weight) and body composition – including rate of change
-very useful in clinical practice as can tell alot about condition (e.g. chronic phase related to chronic clinical condition (unintentional weight loss over long period. e.g. unknown bowel cancer for few years.) vs acute phase related to acute clinical condition (unintentional weight loss over short period/quickly. e.g. could be caused by diarrhea and vomiting. Usually regained in a short period of time))
1. Weight
2. Height (standing up. children under 2 lying down. but some may not people able to be measured e.g. bed bound or wheelchair: use other length measurements which can be put into charts to indicate height) /Stature/knee height/total arm length/arm span (esp. important in paedeatrics. )
3. Circumferences (wasit circumference good indicator for central adiposity)
More invasive rarely used in clinical practise
4. Skinfolds
5. Bioelectrical impedance
6. Body density: under water weighing, BodPod
7. Isotope dilution (total body water)
8. DEXA
9. Total body electrical conductivity
10. Magnetic resonance imaging
BMI
Body Mass Index (BMI)-weight for height in a suggested range
BMI= weight (kg) / Height (m2)
-used alot clinically
World Health Organization 2000 (uses only one cut off). * Only health conditions associated with increasing BMI.
-still a blunt measurement/instrument
-larger lean body mass:fat. therefore actually low risk of disease (Joan Olaumu).-athletes who need to be muscular for their sport
-used to have different cut offs for different ethnic groups, as assumed:
-Pacific Island+ Maori always had higher fat mass:leanbody mass, therefore their cut offs for disease were different(higher). Asian and Indian lower cut offs
Principal BMI cut-off points for adults aged 18 years and over
Underweight = high risk of undernutrition
Percentage Age weight Loss
Change in Body Weight – very useful
1. Unintentional
2. Relate to time
% Weight loss = Usual weight - current weight (kg) x 100 Usual weight
3. Recalled “well” weight often more reliable than standard tables for estimating weight loss
Evaluation of Weight Changes
Time -Significant Weight Loss - Severe Weight Loss 1 week - 1-2% - >2% 1 month - 5% - >5% 3 months - 7.5% - >7.5% 6 months - 10% - >10%
Body composition
Body weight= fat + lean tissue (including water)
a) Ideal Body Fat:
-Men 12-20% body fat
-Women 20-30% body fat
b) Increased Health Risks
– >22% fat in young men & >25% in men over 40
– >32% in young women & >35% in women over 40
Distribution of Body fat
-not only higher BMI but wlaso where fat is increases risk of CDV, Liver diseases and some cancer
May relate to disease independently of obesity (e.g. abdominal fat and type 2 diabetes)
1. Waist:Hip ratio:
– correlates with body fat – increased mortality risk > 0.8 women, >1.0 men
2. Waist circumference:
increased mortality risk > 88 cm women, > 102 cm men
-can be difficult and sensitive to do
-ideally want to do on direct skin, but often done ontop of thin shirt
Waist circumference cut-off points for adults aged 18 years and over
Risk of metabolic complications - Men - Women
Average risk -
Biochemical Assessment
- To detect subclinical or marginal deficiencies (could just look-see malnourished)
- To enhance or support other nutritional data
- Nutrients in blood or urine, biopsy (not many tests are that sensitive to being able to truely evaluate nutritional status, few biochemical biomarkers of nutrients that are reliable)
- In vivo response to nutrient supplementation e.g Hb and iron (response to supplementation or intervention. Want to ensure biochemisty has worked therefore do blood tests eg)
Biochemical Tests examples
- Serum albumin level :Measures main protein in blood ;Determines protein status
- Serum transferrin level - Indicates iron-carrying protein in blood
Clinical and Physical subjective evaluations
Subjective evaluation of overt signs/symptoms-includes medical history
1. Signs & symptoms of deficiency/toxicity whether likely to be reversible)
2. Measurements of physiologic performance and activities -functional status –Oral
and dental health
3. Cognitive status
4. Use of drugs – drug-nutrient interactions etc