Adapted by the State of California CHDP Nutrition Subcommittee from materials developed byCalifornia Department of Health Care Services Children’s Medical Services Branch

Centers for Disease Control and PreventionMaternal and Child Health Bureau

May 2011

Assessing Child Growth Using Body Mass Index (BMI)-for-Age

Growth Charts

Training Objectives

By the end of this presentation, you will be able to:• describe the use of Body Mass Index (BMI) as a

screening tool for overweight and obesity• calculate or determine BMI value from

measured weight and height• plot BMI value on the growth chart• determine BMI-for-age percentile• interpret weight category• record results on PM 160

Obesity Trends in Children and Teens Receiving CHDP Exams

0

5

10

15

20

25

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

% ≥

95t

h pe

rcen

tile

[Insert County]CaliforniaExpected Level

CDC Pediatric Nutrition Surveillance System (PedNSS) Data, 2000-2009.Accessed online at www.dhcs.ca.gov/services/chdp/Pages/PedNSS2009.aspx (accessed 9/30/10).

Ages 5 to < 20

Customize chart with PedNSS data from your county. See User Guide.

Childhood Overweight and Obesityby Age Group

[Insert Your County Name] 2009

15.9

18.7

18.3

22.5

20.2

29.0

20.8

26.2

19.7

21.8

0

10

20

30

40

50

% o

verw

eigh

t or o

bese

2 - < 5 Yrs 5 - 8 Yrs 9 - 11 Yrs 12 - 14 Yrs 15 - < 20 Yrs

Age Group

≥ 95th %ile85th - < 95th %ile

CDC Pediatric Nutrition Surveillance System (PedNSS) Data, 2009.Accessed online at www.dhcs.ca.gov/services/chdp/Pages/PedNSS2009.aspx (accessed 9/30/10).

Customize chart with PedNSS data from your county. See User Guide.

Childhood Overweight and Obesityby Ethnicity

California 2009 [Insert Your County Name]

20.5

17.9

17.7

21.2

19.5

25.2

20.1

26.2

14.1

13.5

21.0

35.5

14.6

18.9

01020304050

% o

verw

eigh

t or

obes

e

≥ 95th %ile 85th - < 95th %ile

CDC Pediatric Nutrition Surveillance System (PedNSS) Data, 2009.Accessed online at www.dhcs.ca.gov/services/chdp/Pages/PedNSS2009.aspx (accessed 9/30/10).

Children Aged 5 to < 20 years

Customize chart with PedNSS data from your county. See User Guide.

What Is Body Mass Index?• A number that compares an individual’s weight to height

• Body Mass Index (BMI) = Weight (kg) / Height (m)²

• As an indirect measure, a screening test for body fatness

• Lifetime tracking tool– Age 2 years through adulthood

• Examines weight, stature and age• Screening for health and nutrition status• Early indicator of other health risk factors

– Hyperlipidemia– Elevated insulin– High blood pressure

Why Use BMI-for-Age?

Body Mass Index-for-Agefor Children and Teens

• Recommended by– Centers for Disease Control– American Academy of Pediatrics– Expert Committee– USPSTF– White House Task Force

• Required by– CHDP– Health Plans

Body Mass IndexCutoff Values for Adults

• Standard weight categories• Same for all ages• Same for men and women

Weight Status BMI

Obese 30.0 and above

Overweight 25.0 - 29.9

Normal 18.5 - 24.9

Underweight Below 18.5

Age 2 4 9 13BMI Value 19.3 17.8 21.0 25.1

For Children, BMI Changes with AgeExample: Child’s growth tracking along 95th percentile

BMI for Children and Teens• Age- and sex-specific• Plot BMI on growth chart to find percentile• Weight status determined by percentile

Weight Status Category Percentile Range

Obese ≥ 95th percentile

Overweight 85th to < 95th percentile

Normal 5th to < 85th percentile

Underweight < 5th percentile

What is a Percentile?

95th

5th

Major Percentile Divisions

85th

50th

Tip: Download and print fromwww.cdc.gov/growthcharts/

Formula to calculate BMI

Published May 30, 2000 (modified 2000-2001)

Percentile lines5th - 10th - 25th - 50th

75th - 85th - 90th - 95th

CDCGrowth Charts

How to Read and Interpretthe Growth Chart

• A single point on the curve indicates current status

• A series of BMI plots are needed to determine the growth trend

• If growth deviates from the expected growth pattern, further assessment may be needed

Adiposity Rebound

• The increase in BMI that occurs after it reaches its lowest point, usually between ages 4 to 6

• Normal growth pattern

↑BMI

AGE →

Adiposity ReboundChild following 10th percentile curve

At what age does the BMI reach its lowest point?

↑BMI

AGE →

Adiposity ReboundChild following 85th percentile curve

At what age does the BMI reach its lowest point?

↑BMI

AGE →

Early Adiposity Rebound

• Early adiposity rebound(before age 5) is related to higher BMI in adulthood

• An increase in BMI percentile < 5 yearsis a red flag

↑BMI

AGE →

Early Adiposity ReboundWithout Intervention With Intervention

↑BMI ↑BMI

AGE → AGE →

Excessive Adiposity Rebound

• Excessive adiposity rebound is related to higher BMI in adulthood

• Increasing BMI percentiles crossing major percentile linesare red flags

↑BMI

AGE →

Steps to Plot BMI-for-age

1. Select appropriate growth chart

2. Measure standing height accurately

3. Measure weight accurately

4. Determine BMI value

5. Determine BMI-for-age percentile

6. Record BMI percentile on PM 160

7. Determine weight category

Chart Carlos Correctly Step 1:

Select Appropriate Growth Chart • Birth to 36 months: Boys or Girls

– Length-for-age– Weight-for-age– Head circumference– Weight-for-length

• 2 to 20 years: Boys or Girls– Stature-for-age– Weight-for-age– BMI-for-age

4 5 3

Date Age Weight Stature BMI*

3 32 # 38 ½ ”

15.2

4 36 # 41 ” 15.0

6 45 ¾ ”

Chart Carlos CorrectlyStep 2: Measure Standing Height

Record on growth chart and PM 160

Chart Carlos CorrectlyStep 3: Measure Weight

Record on growth chart and PM 160

4 5 3 0 4 3 0 8

Date Age Weight Stature BMI*

3 32 # 38 ½ ”

15.2

4 36 # 41 ” 15.0

6 43 ½ #

45 ¾ ”

• English measurementsWt (pounds) ÷ Ht (inches) ÷ Ht (inches) x 703

• Metric measurementsWt (kg) ÷ Ht (cm) ÷ Ht (cm) x 10,000

TIP: Formulas are listed on the BMI-for-age chart

Method 1:

Using a calculator

Chart Carlos Correctly Step 4A: Determine BMI Value

• Find height on inner wheelTIP: Mark with your thumb and index finger

• Line up the height with weight on outer wheel• Read BMI value in the window on the inner wheel

TIP: Read decimal points from right to left!

Method 2:Using aBMI calculation wheel

Chart Carlos CorrectlyStep 4A:Determine BMI Value

Date Age Weight Stature BMI*

3 32 # 38 ½ ”

15.2

4 36 # 41 ” 15.0

6 43 ½ #

45 ¾ ”

14.6

Chart Carlos Correctly Step 4B: Determine BMI Value

Record on growth chart

• Find age on horizontal axis

• Find BMI valueon vertical axis

• Mark point of intersection

• Estimate BMI percentile

TIP: Use a transparentgrowth chart plotting aid

Chart Carlos CorrectlyStep 5: Determine BMI-for-Age %ile

• Estimate a whole number between 1 and 99 that best represents the percentile point plotted on the growth chart

4 5 3 0 4 3 0 82 5

Chart Carlos CorrectlyStep 6:

Record BMI Percentile on PM 160

Weight Status Category Percentile Range

Obese ≥ 95th percentile

Overweight 85th to < 95th percentile

Normal 5th to < 85th percentile

Underweight < 5th percentile

Chart Carlos CorrectlyStep 7A:

Determine Weight Category

• On PM 160, enterfollow up code in appropriate column under “PROBLEM SUSPECTED”

• Enter diagnosis under “COMMENTS/PROBLEMS” – Underweight– Overweight– Obese

Chart Carlos CorrectlyStep 7B: Record Abnormal Results

BMI for 5 year old boy•Weight: 43.5 lb •Height: 43.0 in•BMI= 16.5

• BMI-for-age =75-84th percentile

• Normal range

If height is inaccurate:•Weight: 43.5 lb •Height: 42.5 in•BMI = 17.0

• BMI-for-age = 85-94th percentile

• Overweight range

Accurate Measurements Are Critical

Summary

You are now able to:• describe the use of BMI as a screening tool• determine BMI value• plot BMI value on the growth chart• determine BMI-for-age percentile• interpret weight category• record results on PM 160

Color-coded BMI Charts

• 5210 Let’s Go!www.letsgo.org/

• Eat Smart, Move MoreNorth Carolinawww.eatsmartmovemorenc.com/

• National Initiativefor Children’s Healthcare Qualitywww.nichq.org/ > Childhood Obesity

Growth Assessment Resources

• Essential clinical tools in training packet• Resource handout lists sources for

– Online tutorials– Online resources– Growth charts– Plotting aids– BMI calculators and wheels

CDC BMI Percentile Calculator for Child and TeenCHOP Body Mass Index and Z-Score Calculation in ChildrenShape Up America! Childhood Obesity Assessment Calculator

– Software applications

References• American Academy of Pediatrics Policy Statement:

Prevention of Pediatric Overweight and Obesity. Pediatrics. 112: 424-430, 2003. http://aappolicy.aappublications.org/cgi/content/full/pediatrics;112/2/424

• Assessment of Child and Adolescent Overweight and Obesity.Pediatrics 120: S193-S228, 2007. http://pediatrics.aappublications.org/cgi/content/full/120/Supplement_4/S193

• Expert Committee Recommendations Regarding the Prevention, Assessment,and Treatment of Child and Adolescent Overweight and Obesity: Summary Report. Pediatrics 120 : S164-S192, 2007.http://pediatrics.aappublications.org/cgi/content/abstract/120/Supplement_4/S164

• Recommendations for Prevention of Childhood Obesity.Pediatrics 120 : S229-S253, 2007.http://pediatrics.aappublications.org/cgi/content/abstract/120/Supplement_4/S229

• The Validity of BMI as an Indicator of Body Fatness and Risk Among Children. Pediatrics 124: S23-S34, 2009. http://pediatrics.aappublications.org/cgi/content/abstract/124/Supplement_1/S23