Centers For Disease Control And Prevention

Centers for Disease Control and Prevention

About BMI for Children and Teens

What is BMI?

Body   M ass   I ndex   ( BMI)   i s   a   n umber   c alculated   f rom   a  

child's   w eight   a nd   h eight.   B MI   i s   a   r eliable   i ndicator   o f  

body   f atness   f or   m ost   c hildren   a nd   t eens.   B MI   d oes   n ot  

Obese  

measure   b ody   f at   d irectly,   b ut   r esearch   h as   s hown   t hat  

BMI   c orrelates   t o   d irect   m easures   o f   b ody   f at.   B MI   c an  

be   c onsidered   a n   a lternative   f or   d irect   m easures   o f  

body   f at.   A dditionally,   B MI   i s   a n   i nexpensive   a nd   e asy-­‐

Over-­‐  

to-­‐perform   m ethod   o f   s creening   f or   w eight   c ategories  

Weight  

that   m ay   l ead   t o   h ealth   p roblems.  

 

For   c hildren   a nd   t eens,   B MI   i s   a ge-­‐   a nd   s ex-­‐specific   a nd  

is   o ften   r eferred   t o   a s   B MI-­‐for-­‐age.  

What is a BMI percentile?

Healthy  

Weight  

After   B MI   i s   c alculated   f or   c hildren   a nd   t eens,   t he   B MI  

number   i s   p lotted   o n   t he   C DC   B MI-­‐for-­‐age   g rowth  

charts   ( for   e ither   g irls   o r   b oys)   t o   o btain   a   p ercentile  

ranking.   P ercentiles   a re   t he   m ost   c ommonly   u sed  

indicator   t o   a ssess   t he   s ize   a nd   g rowth   p atterns   o f  

individual   c hildren   i n   t he   U nited   S tates.   T he   p ercentile  

Under-­‐

indicates   t he   r elative   p osition   o f   t he   c hild's   B MI   n umber  

weight  

among   c hildren   o f   t he   s ame   s ex   a nd   a ge.   T he   g rowth  

charts   s how   t he   w eight   s tatus   c ategories   u sed   w ith  

children   a nd   t eens   ( underweight,   h ealthy   w eight,  

overweight,   a nd   o bese).  

 

BMI-­‐for-­‐age   w eight   s tatus   c ategories   a nd   t he   c orresponding   p ercentiles   a re   s hown   i n   t he   f ollowing   t able.  

 

Weight Status Category

Percentile Range

Underweight  

Less   t han   t he   5 th   p ercentile  

Healthy   w eight  

5th   p ercentile   t o   l ess   t han   t he   8 5th   p ercentile  

Overweight  

85th   t o   l ess   t han   t he   9 5th   p ercentile  

Obese  

Equal   t o   o r   g reater   t han   t he   9 5th   p ercentile  

 

How is BMI used with children and teens?

BMI   i s   u sed   a s   a   s creening   t ool   t o   i dentify   p ossible   w eight   p roblems   f or   c hildren.   C DC   a nd   t he   A merican   A cademy   o f  

Pediatrics   ( AAP)   r ecommend   t he   u se   o f   B MI   t o   s creen   f or   o verweight   a nd   o besity   i n   c hildren   b eginning   a t   2   y ears   o ld.  

 

For   c hildren,   B MI   i s   u sed   t o   s creen   f or   o besity,   o verweight,   h ealthy   w eight,   o r   u nderweight.   H owever,   B MI   i s   n ot   a  

diagnostic   t ool.   F or   e xample,   a   c hild   m ay   h ave   a   h igh   B MI   f or   a ge   a nd   s ex,   b ut   t o   d etermine   i f   e xcess   f at   i s   a   p roblem,   a  

health   c are   p rovider   w ould   n eed   t o   p erform   f urther   a ssessments.   T hese   a ssessments   m ight   i nclude   s kinfold   t hickness  

measurements,   e valuations   o f   d iet,   p hysical   a ctivity,   f amily   h istory,   a nd   o ther   a ppropriate   h ealth   s creenings.  

Reference

About BMI for Children and Teens. (2011, September 13). Retrieved from Centers for Disease Control website: