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CDC Growth Charts 2000
Centers for Disease Control and PreventionNational Center for Chronic Disease Prevention and Health
Promotion
Division of Nutrition and Physical Activity
Maternal and Child Nutrition Branch
Revised June 2002
Training ObjectivesTraining Objectives
Science behind development of growtScience behind development of growth chartsh charts
Rationale for including BMI-for-ageRationale for including BMI-for-age
Using BMI-for-age as a screening toolUsing BMI-for-age as a screening tool
What growth charts are available?
• BMI-for-age charts (2-20 years)
• 85th percentile (at risk of overweight)
• 3rd and 97th percentiles available
• Lower limits of length (45 vs. 49 cm) and height (77 vs. 90 cm) extended
• Smoothed percentile curves and z-scores agree
• Correction in the disjunction
• BMI-for-age charts (2-20 years)
• 85th percentile (at risk of overweight)
• 3rd and 97th percentiles available
• Lower limits of length (45 vs. 49 cm) and height (77 vs. 90 cm) extended
• Smoothed percentile curves and z-scores agree
• Correction in the disjunction
New Features of the Growth New Features of the Growth ChartsCharts
New Features of the Growth New Features of the Growth ChartsCharts
Disjunction: Smoothed in New Disjunction: Smoothed in New ChartsCharts
40
50
60
70
80
90
100
110
120
0 6 12 18 24 30 36 42 48 54 60Age in month
Len
gth
/heig
ht
in c
m
40
50
60
70
80
90
100
110
120
0 6 12 18 24 30 36 42 48 54 60Age in month
Len
gth
/heig
ht
in c
m
1977 2000
• Racially and ethnically Racially and ethnically diverse diverse
• Infants: Birth to 36 monthsInfants: Birth to 36 months
• Children and Adolescents: 2 Children and Adolescents: 2 to 20 to 20 yearsyears
• Breast- and formula-fed Breast- and formula-fed infantsinfants
• Racially and ethnically Racially and ethnically diverse diverse
• Infants: Birth to 36 monthsInfants: Birth to 36 months
• Children and Adolescents: 2 Children and Adolescents: 2 to 20 to 20 yearsyears
• Breast- and formula-fed Breast- and formula-fed infantsinfants
Reference Population for Reference Population for CDC Growth ChartsCDC Growth Charts
Reference Population for Reference Population for CDC Growth ChartsCDC Growth Charts
Reference Data Sets: Birth to 36 Reference Data Sets: Birth to 36 Months Months
Weight-for-Length
Weight
Length
Head Circum
MO/WI Natality National Natality PedNSS
Fels NHANES III ('88-'94) NHANES II ('76-'80)
NHANES I ('71-'74)
B 3 6 9 12 15 18 21 24 27 30 33 36 Age in Months
Reference Data Sets: 2 to 20 Years Reference Data Sets: 2 to 20 Years
Weight/BMI
Stature
NHANES III ('88-'94) NHANES II ('76-'80) NHES II ('63-65)
NHES III ('66-'70) NHES II ('63-'65)
2 4 6 8 10 12 14 16 18 20
Age in Years
Exclusions from the Reference Exclusions from the Reference DataData
Very low birth weight (VLBW) Very low birth weight (VLBW) infants (<1500 g) were excluded infants (<1500 g) were excluded because they have different because they have different growth patternsgrowth patterns
NHANES III weight data for 6+ NHANES III weight data for 6+ year olds were excluded to year olds were excluded to avoid an upward shift in weight-avoid an upward shift in weight-for-age and BMI-for-age curvesfor-age and BMI-for-age curves
11>95>95thth percentile BMI-for-age percentile BMI-for-age 2 2
http://www.cdc.gov/nchs/products/pubs/pubd/hestats/overwghttp://www.cdc.gov/nchs/products/pubs/pubd/hestats/overwght99.htmht99.htm
11>95>95thth percentile BMI-for-age percentile BMI-for-age 2 2
http://www.cdc.gov/nchs/products/pubs/pubd/hestats/overwghttp://www.cdc.gov/nchs/products/pubs/pubd/hestats/overwght99.htmht99.htm
Age-Adjusted Prevalence of Overweight1 From NHANES I to III 2
Age-Adjusted Prevalence of Overweight1 From NHANES I to III 2
0
5
10
15
20
Boys 6-11 y Boys 12-17 y Girls 6-11 y Girls 12-17 y
NHANES I I I I I I
Sex and Age GroupSex and Age Group
Perc
en
tP
erc
en
t
CDC Growth Charts Are for All CDC Growth Charts Are for All Racial and Ethnic Racial and Ethnic
Groups CombinedGroups Combined• Environmental influences appear to contribute to variations in growth more than genetic influences
• Inadequate sample data for racial- and ethnic- specific charts
• The effect of race and ethnicity on BMI-for- age is unclear
Age Adjusted Prevalence of Low Age Adjusted Prevalence of Low Height-for-Age by Ethnic Height-for-Age by Ethnic
Groups, Groups, ChildrenChildren Aged 0 to 5 Aged 0 to 5 YearsYears11
Age Adjusted Prevalence of Low Age Adjusted Prevalence of Low Height-for-Age by Ethnic Height-for-Age by Ethnic
Groups, Groups, ChildrenChildren Aged 0 to 5 Aged 0 to 5 YearsYears11
0
5
10
15
79 80 81 82 83 84 85 86 87 88 89 90 91 92 93
WhiteAsian
Year of Visit Year of Visit
Perc
en
tag
e
1 Mei, Yip and Trowbridge, Asia Pacific J Clin Nutr 1998; 7(2): 111-116
Breast-Fed vs. Formula-Fed Breast-Fed vs. Formula-Fed Infants Infants
Mode of infant feeding can influence Mode of infant feeding can influence growth growth
New charts represent the combined growth New charts represent the combined growth patterns of breast-fed and formula-fed patterns of breast-fed and formula-fed infantsinfants
Working group of the World Health Working group of the World Health Organization (WHO) is developing growth Organization (WHO) is developing growth charts for infants and children through age charts for infants and children through age 5 using data collected on infants following 5 using data collected on infants following WHO feeding recommendationsWHO feeding recommendations
Indicators of Nutritional Indicators of Nutritional StatusStatus
<5th percentileStunting/shortness length or stature-for-age
Head circumference-for-age
<5th percentile
<5th percentile>95th percentile
Underweight weight-for-length BMI-for-age
Indicators of Nutritional Indicators of Nutritional StatusStatus
Overweight Weight-for-length BMI-for-age
>95th percentile
Risk of overweight BMI-for-age
85th to 95th percentile
Prevalence of Nutritional Status Prevalence of Nutritional Status Indicators New Reference Indicators New Reference
Curves Compared with Old Curves*Curves Compared with Old Curves*
< 2 Years OldNutrition Indicator Change in Prevalence
Stunting/shortnesslength-for-age <5th
1% to 2% lower
Underweightweight-for-length <5th
* NHANES III
Overweightweight-for-length >95th
2% lower for females2% higher for males
1% to 2% higher
Prevalence of Nutritional Status Prevalence of Nutritional Status Indicators New Reference Indicators New Reference
Curves Compared with Old CurvesCurves Compared with Old Curves**
Children 2 to 5 years of age
Nutrition Indicator Change in Prevalence
Stunting/shortnessstature-for-age <5th
1% lower
Underweight** <5th 3% to 4% higher
* NHANES III**BMI-for-age, weight-for-stature
Overweight** 95th No change for females1% higher for males
What Is BMI?What Is BMI?What Is BMI?What Is BMI?
• Body mass index (BMI) = Body mass index (BMI) =
weight (kg)/height (m)weight (kg)/height (m)22
• BMI is an effective screening tool; it BMI is an effective screening tool; it is not a diagnostic toolis not a diagnostic tool
• For children, BMI is age and gender For children, BMI is age and gender specific, so BMI-for-age is the specific, so BMI-for-age is the measure usedmeasure used
• Body mass index (BMI) = Body mass index (BMI) =
weight (kg)/height (m)weight (kg)/height (m)22
• BMI is an effective screening tool; it BMI is an effective screening tool; it is not a diagnostic toolis not a diagnostic tool
• For children, BMI is age and gender For children, BMI is age and gender specific, so BMI-for-age is the specific, so BMI-for-age is the measure usedmeasure used
Advantages of BMI-for-AgeAdvantages of BMI-for-AgeAdvantages of BMI-for-AgeAdvantages of BMI-for-Age
Provides a reference for Provides a reference for adolescents that was not adolescents that was not previously availablepreviously available
Consistent with adult index so it Consistent with adult index so it can be used continuously fromcan be used continuously from2 2 years of age to adulthoodyears of age to adulthood
Tracks childhood overweight into Tracks childhood overweight into adulthood adulthood
Provides a reference for Provides a reference for adolescents that was not adolescents that was not previously availablepreviously available
Consistent with adult index so it Consistent with adult index so it can be used continuously fromcan be used continuously from2 2 years of age to adulthoodyears of age to adulthood
Tracks childhood overweight into Tracks childhood overweight into adulthood adulthood
Tracking BMI-for-Age from Birth to 18 Tracking BMI-for-Age from Birth to 18 Years with Percent of Years with Percent of
Overweight Children who Are Obese at Age Overweight Children who Are Obese at Age 252511
16 15 12 11 10 917 19
55
7567
26
52
69
8377
36
0
20
40
60
80
100
Birth 1 to 3 3 to 6 6 to 10 10 to 15 15 to 18
Age of child (years)
% o
bes
e as
ad
ult
s
BMI < 85th BMI >=85th BMI >=95th
Whitaker et al. NEJM: 1997;337:869-873
Advantages of BMI-for-AgeAdvantages of BMI-for-AgeAdvantages of BMI-for-AgeAdvantages of BMI-for-Age
BMI-for-age relates to health risksBMI-for-age relates to health risks
Correlates with clinical risk factors for cardCorrelates with clinical risk factors for cardiovascular disease including hyperlipidemiiovascular disease including hyperlipidemia, elevated insulin, and high blood pressura, elevated insulin, and high blood pressuree
BMI-for-age during pubescence is related tBMI-for-age during pubescence is related to lipid levels and high blood pressure in mio lipid levels and high blood pressure in middle ageddle age
BMI-for-age relates to health risksBMI-for-age relates to health risks
Correlates with clinical risk factors for cardCorrelates with clinical risk factors for cardiovascular disease including hyperlipidemiiovascular disease including hyperlipidemia, elevated insulin, and high blood pressura, elevated insulin, and high blood pressuree
BMI-for-age during pubescence is related tBMI-for-age during pubescence is related to lipid levels and high blood pressure in mio lipid levels and high blood pressure in middle ageddle age
• Weight-for-stature measurements 1
• Measures of body fat
BMI-for-Age Compares Well with
Mei et al., Am J Clin Nutr 2002;75:978-85.
Why Use BMI-for-Age?Why Use BMI-for-Age?Why Use BMI-for-Age?Why Use BMI-for-Age?• Recommended by expert committees to Recommended by expert committees to
evaluate overweightevaluate overweight• Recommended by expert committees to Recommended by expert committees to
evaluate overweightevaluate overweight
Guidelines for Overweight in Adolescent Preventive
Services (Am J Clin Nutr 1994;59:307-316) Obesity Evaluation and Treatment: Expert Committee Recommendations (Pediatrics 1998 Sept;(102)3:e 29) Assessment of Childhood and Adolescent Obesity: International Obesity Task Force (Am J Clin Nutr 1999, 70,suppl)
Shape of Weight-for-Stature Shape of Weight-for-Stature Curve versus BMI-for-Age Curve versus BMI-for-Age
CurveCurve
10
15
20
25
30
35
24 72 120 168 216
Age (months)
BM
I0
5
10
15
20
25
30
35
80 90 100110120130
Stature (cm)
Wei
gh
t (k
g)
95th
50th
5th
95th
50th
5th
Example: 95th Percentile Tracking Age BMI
2 yrs 19.3 4 yrs 17.8 9 yrs 21.013 yrs 25.1
For Children, BMI Changes with Age
Boys: 2 to 20 years
BMI BMI
BMI BMI
Shape of BMI-for-Age Growth Curve: “Adiposity” Rebound (AR)
Example: Early AR
Age (mos) BMI 26 18.2 32 17.4 38 18.5 41 18.7
Boys: 2 to 20 years
BMI BMI
BMIBMI
BMI
BMI-for-Age CutoffsBMI-for-Age CutoffsBMI-for-Age CutoffsBMI-for-Age Cutoffs
> 95th percentile Overweight
85th to < 95th Risk of overweight percentile
< 5th percentile Underweight
Using the 85Using the 85thth and 95 and 95thth percentiles as percentiles as cut points, few children are incorrectly cut points, few children are incorrectly identified as over-fat but some over-identified as over-fat but some over-fat children will be missed.fat children will be missed.
It is desirable to correctly identify It is desirable to correctly identify those children not at risk of those children not at risk of overweight or overweight.overweight or overweight.
Performance of BMI-for-Age as a
Screening Tool
Formula:Formula: weight (kg)/[height (m)]weight (kg)/[height (m)]2 2
Calculation:Calculation: [ [weight (kg)/ height (cm)/ weight (kg)/ height (cm)/
height (cm)] x 10,000height (cm)] x 10,000
Formula:Formula: weight (kg)/[height (m)]weight (kg)/[height (m)]2 2
Calculation:Calculation: [ [weight (kg)/ height (cm)/ weight (kg)/ height (cm)/
height (cm)] x 10,000height (cm)] x 10,000
Calculating BMI with the Calculating BMI with the Metric SystemMetric System
Calculating BMI with the Calculating BMI with the Metric SystemMetric System
Example: A child’s weight=16.9 kg and height=105.4 cm
BMI = [16.9 kg / 105.4 cm / 105.4 cm] x 10,000 = 15.2
Calculating BMI with the English Calculating BMI with the English SystemSystem
Calculating BMI with the English Calculating BMI with the English SystemSystem
Formula: Formula: weight (lb)/[height (in)]weight (lb)/[height (in)]22 x x 703703
Calculation:Calculation: [ [weight (lb)/height (in)/height weight (lb)/height (in)/height (in)] x 703(in)] x 703
Formula: Formula: weight (lb)/[height (in)]weight (lb)/[height (in)]22 x x 703703
Calculation:Calculation: [ [weight (lb)/height (in)/height weight (lb)/height (in)/height (in)] x 703(in)] x 703
Example: A child’s weight = 37 pounds, 4 ounces and height = 41 1/2 inches (convert fractions to decimal value)
BMI = [37.25 lb / 41.5 in / 41.5 in] x 703 = 15.2
Can you see risk?
• This boy is 3 years, 3 weeks old.
• Is his BMI-for-age
- >85th to <95th percentile: at risk for overweight?
Photo from UC Berkeley Longitudinal Study, 1973
Measurements:
Age=3 y 3 wks
Height=100.8 cm (39.7
in)
Weight=18.6 kg (41
lb)
BMI=18.3
BMI-for-age= >95th percentile overweight
Plotted BMI-for-Age
Boys: 2 to 20 years
BMI BMI
BMI BMI
Can you see risk?
• This girl is 4 years, 4 weeks old.
• Is her BMI-for-age
- >85th to <95th percentile: at risk for overweight?
Photo from UC Berkeley Longitudinal Study, 1974
Measurements:
Plotted BMI-for-Age
Girls: 2 to 20 years
Age= 4 y 4 wks
Height=106.4 cm
(41.9 in)
Weight=15.7 kg
(34.5 lb)
BMI=13.9
BMI-for-age= 10th percentile Normal
BMI BMI
BMIBMI
Can you see risk?
• This girl is 4 years old.• Is her BMI-for-age
- >85th to <95th percentile: at risk for overweight?
Photo from UC Berkeley Longitudinal Study, 1973
Measurements: Age=4 y
Height=99.2 cm (39.2 in)
Weight=17.55 kg (38.6
lb)
BMI=17.8
BMI-for-age= between 90th –95th percentile At risk for overweight
Plotted BMI-for-Age
Girls: 2 to 20 years
BMI
BMIBMI
BMI
5 1/2 year old boy
Weight: 41.5 lb
Height: 43 in
BMI= 15.8
BMI-for-age=50th %tile
Inaccurate height measurement: 42.25
BMI=16.3
BMI-for-age=75th %tile
Accurate Measurements are Critical
Boys: 2 to 20 years
BMI BMI
BMI BMI
Interpreting the BMI-for-Age Interpreting the BMI-for-Age CutoffsCutoffs
Interpreting the BMI-for-Age Interpreting the BMI-for-Age CutoffsCutoffs
> 95th percentile Overweight
85th to < 95th Risk of overweight percentile
< 5th percentile Underweight
Interpreting the BMI-for-Age Interpreting the BMI-for-Age Chart Chart
BMI-for-age indicates a child’s BMI-for-age indicates a child’s weight in relation to his/her weight in relation to his/her height for a specific age and height for a specific age and gendergender
Need a series of BMI plots to Need a series of BMI plots to
determine the growth trenddetermine the growth trend
If indices deviate from normal If indices deviate from normal growth patterns, further growth patterns, further assessment may be neededassessment may be needed
Example: “Sam” Example: “Sam”
Name: SamName: Sam Weight: 37 lb 4 oz (16.9 kg)Weight: 37 lb 4 oz (16.9 kg) Height: 41.5 inches (105 cm)Height: 41.5 inches (105 cm) Age: 3.5 yearsAge: 3.5 years BMI: 15.2BMI: 15.2
Sam’s BMI Plotted on Boy’s BMI-Sam’s BMI Plotted on Boy’s BMI-for-Age Chartfor-Age Chart
Interpretation:
• Sam’s BMI-for-age is slightly below the 25th %tile so it falls within the normal range.
• Of 100 boys who are the same age, fewer than 25 have a BMI-for-age lower than Sam’s.
Boys: 2 to 20 years
BMI BMI
BMI BMI
Summary of Using BMI-for-Age
• BMI-for-age is the recommended method for screening overweight and underweight
• For children, BMI is age and gender specific; for adults there are fixed cut points
• Accurate and periodic measurements are important elements of any anthropometric screening
Steps to Plot BMI-for-AgeSteps to Plot BMI-for-Age
Obtain accurate weight and Obtain accurate weight and height measurements height measurements
Select the appropriate growth Select the appropriate growth chartchart
Record the dataRecord the data Calculate BMICalculate BMI Plot measurementsPlot measurements Interpret plotted measurementsInterpret plotted measurements
• For additional training materials related to the growth charts
• For tools related to the growth charts
• To download the growth charts
Please visit:
http://www.cdc.gov/growthcharts/
