Nutritional Assessment

Focusing on Office Anthropometrics

Joan Temmerman, MD, MS, FAAFP, CNS

Medical Bariatrician, Clarian BariatricsAssistant Professor of Clinical Medicine, Dept. of Medicine, Indiana University School of MedicineDiplomate, American Board of Bariatric MedicineDiplomate, American Board of Family MedicineFellow, American Academy of Family PhysiciansCertified Nutrition Specialist

Objectives

• Review specific issues in providing respectful care for bariatric patients

• Apply nutritional assessment to bariatric patients

• Define anthropometrics• Discuss importance• Review techniques and methods• Review equipment used

Everyone on the Healthcare Team is important!

Beauty comes in all shapes and sizes

Empathetic encounters

• Patient-centered interactions• Respect and sensitivity• Communication

– establishing rapport– attentive listening– exploration of concerns

• Avoid criticizing patients Partnership

Empathetic encounters user-friendly office

• Accessibility to office• Office comfortable• Sturdy armless chairs• Adequate restrooms• Large gowns• Step stool for exam tables• Adequate equipment

Nutritional Assessment

• Dietary assessment• Anthropometrics• Biochemical tests• Clinical evaluation

Dietary Assessment Tools

1. weight history 2. dieting history 3. dietary patterns

• food diary or daily food record (3 day diet record) • food frequency questionnaire • 24 hour recall • diet history interview

What are Anthropometrics?

• The physical dimensions and composition of the body

• Anthropometry is the measurement of body size, weight, and

proportions

• Valuable for assessing nutritional status

Lee RD, Nieman DC. Nutritional Assessment, 5th edition, 2010.

Anthropometrics

• Height (stature)• Weight• BMI• Body composition• Circumferences

• Important clinical decisions based on weight and stature

• Measurements must be as accurate and precise as possible

Measuring Height (stature)

• Do not just ask!• No shoes!!

• Head positioned in Frankfort horizontal plane

Frankfort horizontal plane

Stadiometer • Beam perpendicular• Eyes looking straight ahead• Heels together; toes pointed

slightly outward• Weight evenly distributed• Contact points: -both heels

-buttocks-shoulder blades-back of head

• Deep breath; stand as tall as possible

Weight

• One of the most important measurements

• Private setting• Scale that can weigh all

patients• Record weight silently• Avoid making

comments (focus on non-weight

outcomes)

Limitations of weight

• Does not give information about how much fat, muscle or bone (body composition)

• Muscular person may have “abnormal” weight

• “Normal” weight may mask excess fat

• Obesity= excess body fat (not excess weight)

Body Mass Index (BMI)

• Height and weight must be accurate to calculate BMI correctly

• BMI most widely used measurement to assess weight status

BMI

Limitations of BMI

• Does not directly measure body fat• Does not provide information on body

composition• May be abnormal for muscular person• Doesn’t predict fat distribution• Doesn’t take into account age or

gender

13% body fat 26% body fat

Limitations of BMI

Body Composition

The quality of weight (i.e. fat and lean tissue) is more important

than weight quantity

Body Composition

weight

% fat free mass(lean body mass)

% fat mass

What is normal range of body fat?

• Guidelines vary• As people age, they tend to

lose muscle mass and gain fat

• Sarcopenic obesity: BMI < 27; body fat > 30%

Healthy body fat women: 20-35%

Healthy body fat men: 8-22%

Methods to measure body composition

• Hydrostatic (underwater) weighing • Skinfold measurements • Bioelectrical Impedance Analysis

(BIA) • Air displacement (Bod Pod)• Dual energy x-ray absorptiometry

(DEXA)

Hydrostatic (underwater) Weighing

• The volume of submerged object = volume of displaced water

• Standard laboratory (research) technique

• 2-4% error rate• Not practical for

testing large nos.

• Patient submerged• All air expelled from

lungs• 3-4 measurements

averaged• Takes about 20 min• Uncomfortable &

difficult for some• Requires specialized

equipment & training

Skinfold measurements

calipers

Skinfold measurements

Skinfold limitations

• Error rate 5-10%• May be difficult in obese patients• Hard to locate proper site• Skinfold may be too large for caliper• Reliability of measurements in obese

unknown; not accurate in extremely obese

Blackburn,G. Ed., 1994. Obesity Pathophysiology Psychology and Treatment

Bioelectrical Impedance Analysis (BIA)

• Painless electrical current; instrument measures resistance

• The more water, the easier the current passes through

• Muscle holds more water (greater conductivity)

• More fat, higher resistance

• Calculates body water, fat-free mass and body fat %

Bioelectrical Impedance Analysis (BIA)

• More accurate than skinfold measurements: error rate 4%

• Affected by hydration: -Dehydration increases resistance,

overestimates body fat, -Pedal edema may decrease resistance,

underestimate body fat.

• Contraindicated for pacemakers and defibrillators

BIA

Tanita

BIOELECTRICAL IMPEDANCE ANALYSIS (BIA) SEGMENTAL SCALE

Air Displacement Plethysmography: Bod Pod

Bod Pod

• Similar to water displacement except air displaced

• Rapid, accurate analysis (3-5% error)• Easy for special populations (elderly,

disabled, children)• Provides resting metabolic rate (RMR)

and total energy expenditure (TEE)• Costly (machine ~ $40,000)

Dual energy x-ray absorptiometry (DEXA)

DEXA

• Originally developed to assess bones

• Widely used for body composition

• Quick (3 minutes), safe

• Measurements may be affected by thickness and bone

Circumferencesmeasurements of specific areas

-Waist -Hips -Chest-Neck -Arm -Thighs

Waist Circumference (WC)

• Distribution of fat very important

• Apple shape high risk• Abnormal WC linked to

cardiometabolic disease (≥35 inches F; ≥40

M)

• Superior to BMI in predicting health risks

Fat distribution critical

• Energy is stored in adipose tissue

• Largest organ in body• Extensive blood

supply

• Excess intra- abdominal fat (apple shape) is high-risk

Increased abdominal fat

• Independent risk factor, even when BMI is not markedly increased

• WC better predictor of total abdominal fat than waist-to-hip ratio (WHR)

Measure waist to detect abdominal obesity

Landmarks: top of iliac crest (hip bone)

Measuring waist with pannus

Hips largest circumference below umbilicus

hips

thigh

Measurements

Thigh: just below gluteal fold

neck

Other office measurements

• Vital signs• Include BMI and waist circumference

as vital signs

• Blood pressure

Measuring Blood Pressure

• Correct cuff size critical

• Use larger BP cuffs when appropriate

• Large adult cuff: mild to moderate obesity

• Thigh cuff: severe obesity (arm>16 inches)

• Patient sitting; arm relaxed; elbow heart level

Anthropometrics• Simple, safe, non-invasive• Inexpensive, portable equipment• Produce accurate and precise data when

obtained by trained personnel

• Assess long-term nutritional status• Disadvantages:

– Don’t assess short-term nutritional status– Unable to assess nutritional deficiencies

Boyle MA, Holben DH. Community Nutrition in Action, 5th edition, 2010.

Summary

• Accurate anthropometric measurements

are cornerstone of nutritional assessment

• BMI screens for degree of obesity• Body composition (weight quality)

key measurement• Fat distribution predicts health risks

Additional Resources

• follow this link to view the process for obtaining an accurate height: http://www.youtube.com/watch?v=0LNCuP24MSc.

• follow the following link to view proper technique for obtaining an arm circumference, waist circumference, buttocks circumference and thigh circumference:http://www.youtube.com/watch?v=KacU_TW50Zo.

Additional Resources

• To view the techniques for conducting a subscapular measurement, suprailiac skinfold measurement, and biocromial breadth follow this video link: http://www.youtube.com/watch?v=SXFSvTCHPXo

• Follow this video link to see how a Bod Pod is used to measure body composition: http://www.youtube.com/watch?v=elobnbT33yo