CDC Growth Charts 2000

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CDC Growth Charts 2000
Centers for Disease Control and
Prevention National Center for Chronic Disease
Prevention and Health Promotion Division of
Nutrition and Physical Activity Maternal and
Child Nutrition Branch
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Outline of Presentation

• Why new growth charts?
• What is the difference?
• Available growth charts
• BMI as a screening tool
• Plotting BMI for age
• CDC website

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Why New Growth Charts?

• Data from 1929 to 1975
• White middle-class infants
• Formula-fed infants
• Difference between recumbent length and stature
  measurements between 24 and 36 months

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What is the Difference? Mult-Racial Groups
Combined

• Based on recent data
• Multi-racial sample 1
  Native American
• Inadequate evidence for race specific charts
• Environmental
  factors

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What is the Difference? Breast-Fed vs.
Formula-Fed Infants

• Mode of infant feeding can influence growth
• New charts represent the combined growth patterns
  of breast-fed and formula-fed infants
• Separate charts are not recommended
• Working group of the World Health Organization
  (WHO) is collecting data on infants following the
  WHO feeding recommendations to develop charts for
  infants and children through age 5.

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What is the Difference?
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CDC Growth Charts

• Birth to 36 months
• Weight-for-length
• Length-for-age
• Weight-for-age
• Head circumference-for-age

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CDC Growth Charts

• 2 to 20 years
• BMI-for-age
• Stature-for-age
• Weight-for-age
• Weight-for-height

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New in the CDC Growth Charts
? Charts extend from 18 to 20 years ? 3rd
and 97th percentiles available ? BMI-for-age
charts (2-20 years) added ? 85th percentile
(at risk of overweight) added
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What Is BMI?

• Body mass index (BMI)
• weight (kg)/height (m)2
• BMI is an effective screening tool it is not a
  diagnostic tool
• For children, BMI is age and gender specific, so
  BMI-for-age is the measure used

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Advantages of BMI-for-Age

• BMI-for-age relates to health risks
• Correlates with clinical risk factors for
  cardiovascular disease including hyperlipidemia,
  elevated insulin, and high blood pressure
• BMI-for-age during pubescence is related to lipid
  levels and high blood pressure in middle age

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Advantages of BMI-for-Age

• Provides a reference for adolescents that was not
  previously available
• Consistent with adult standards so can be used
  continuously from 2 years of age to adulthood
• Tracks childhood overweight into adulthood

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Advantages of BMI-for-Age

• Tracks childhood overweight into adulthood
• 1 out of 4 children overweight at 6 yrs will be
  overweight as adults
• 3 out of 4 children overweight at 12 yrs will be
  overweight as adults

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BMI-for-Age Cutoffs

• gt 95th percentile Overweight
• 85th to lt 95th Risk of overweight
• percentile
• lt 5th percentile Underweight

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For Children, BMI Differs by Age
BMI
BMI
Example 95th Percentile Tracking Age
BMI 2 yrs 19.3 4 yrs 17.8 9 yrs
21.0 13 yrs 25.1
Boys 2 to 20 years
BMI
BMI
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Calculating BMI with the Metric System
Formula weight (kg)/height
(m)2 Calculation weight (kg)/
height (m)/
height (m)
Example A childs weight16.9 kg and height1.05
m BMI 16.9 kg / 1.05 m / 1.05 m 15.3
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Can you see risk?

• This boy is 3 years, 3 weeks old.
• Is his BMI-for-age
• - below the 5th percentile?
• - 5th to lt85th percentile normal?
• - gt85th to lt95th percentile at risk for
  overweight?
• - gt95th percentile overweight?

Photo from UC Berkeley Longitudinal Study, 1973
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Plotted BMI-for-Age
Measurements Age3 y 3 wks Height100.8 cm
(39.7 in) Weight18.6 kg (41 lb) BMI?
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Plotted BMI-for-Age
Measurements

• BMI18.3
• BMI-for-age gt95th percentile
  overweight

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Can you see risk?

• This girl is 4 years, 4 weeks old.
• Is her BMI-for-age
• - below the 5th percentile?
• - 5th to lt85th percentile normal?
• - gt85th to lt95th percentile at risk for
  overweight?
• - gt95th percentile overweight?

Photo from UC Berkeley Longitudinal Study, 1974
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Plotted BMI-for-Age
Measurements
BMI
BMI
Age 4 y 4 wks Height106.4 cm (41.9
in) Weight15.7 kg (34.5 lb) BMI?
BMI
BMI
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Plotted BMI-for-Age
Measurements
Girls 2 to 20 years

• BMI13.9
• BMI-for-age 10th percentile
  Normal

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Can you see risk?

• This girl is 4 years old.
• Is her BMI-for-age
• - below the 5th percentile?
• - 5th to lt85th percentile normal?
• - gt85th to lt95th percentile at risk for
  overweight?
• - gt95th percentile overweight?

Photo from UC Berkeley Longitudinal Study, 1973
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Plotted BMI-for-Age
Measurements Age4 y Height99.2 cm
(39.2 in) Weight17.55 kg
(38.6 lb) BMI?
BMI
BMI
BMI
BMI
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Plotted BMI-for-Age
Girls 2 to 20 years

• Measurements
• BMI17.8
• BMI-for-age 94thpercentile
  At risk for overweight

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Accurate Measurements are Critical
5 1/2 year old boy Weight 20 kg Height 110
cm BMI ? Inaccurate height measurement 107
cm BMI?
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Accurate Measurements are Critical

• 5 1/2 year old boy
• Weight 20 kg
• Height 110 cm
• BMI 16.5
• BMI-for-age75th tile
• Inaccurate height measurement 107 cm
• BMI17.5
• BMI-for-age86th tile

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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

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Steps to Plot BMI-for-Age

• Select appropriate growth chart
• Record data
• Obtain accurate weight and height measurements
• Calculate BMI
• Plot measurements
• Interpret plotted measurements

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Interpreting the BMI-for-Age Chart

• BMI-for-age indicates a childs weight in
  relation to his/her height for a specific age and
  gender
• Need a series of BMI plots to determine the
  growth trend
• If indices deviate from normal growth patterns,
  further assessment may be needed

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Distribution of CDC Growth Charts
Electronic Copies
http//www.cdc.gov/growthcharts/