In this section we will first take a look 3 normal growth trends and then
3 abnormal growth trends that can be detected by our growth charts. These examples are the most common type of
growth variations I see everyday. However, it's not exhaustive nor comprehensive, thus if you spot any concerns, always consult with your pediatrician. Before we start, make sure you
understand how to calculate your child's midparental height.
Below are 3 boys represented by their individual colors: purple,
green and red represent 3 each boyc. All 3 are considered to
have normal weight, height and growth velocity. We will now go through these 3 examples and understand why.


RED boy:
A quick glance shows he started as a smaller
child (both in height and weight). However, his final adult height (we
consider that to be reached around 18 for most individuals) actually
places his near 75%, even though his weight remained < 10%. We
also consider this child to be a normal, a classic example of a thin child who has "constitutional delay" in growing, also know as a "late grower."
These children like his parents, may have delayed puberty. However, if this boy has an abnormal physical exam, atypical
features, mental delays, etc., further workup should be by your pediatrician.

PURPLE boy:
A quick glance shows that he started as a
big child and became a big adult, growing consistently above 97% for weight and
height through out his life. For the PURPLE boy, it is
important to make sure his BMI % does not exceed > 85%, which is
considered overweight.
GREEN boy:
He starts his height ~ 7590% and weight is ~
1025%. When looking at this young boy, you will see a thin but tall child. So is he considered underweight? Yes and no.
YES, because proportionally his weight can be and should be at ~ 7590% matching his
height %. So to calculate what his ideal body weight could be to match his height %, simply find the 7590% curve on the weight curves and intersect at the any age, this will tell you where his weight can be at. For example, at age 4, he weighs ~ 32 lbs at 1025%. Moving his weight percentile to match his height to 7590%, he can weight more than 40 lbs.
NO, because as we track his growth velocity for his weight and
height, we see that he remains consistently between 1025% for his
weight, but his height remains also within 7590%. Thus even
though this is a thin child turning eventually into a thin adult, his lower percentiles for his weight does not prevent him from reaching his predicted midparental height (or calculated final adult height). Therefore, the trend is just as
important to monitor as the actual percentiles.

Now lets take a look at the 3
girls who are considered to have abnormal growth detected by plotting a growth . Again they start off at their predicted midparental height. *
The light bulb indicates where the subtle abnormalities that may only
be picked up from a well plotted medical growth chart *
 
BLUE girl: At age 2, she is at 75% for height and 25%
for weight, so she starts off thin or less weight proportionally to
her height. However, note around age 10 her weight velocity has
accelerated to 75% (> 2 SDs). By age 14 she is at
90% for weight, and by 18 she's at 97% for weight while her height
remains the same at 75%. This is a classic pattern of a child gaining
excessive weight during adolescent years and ultimately becoming
overweight, if not intervened she will be an obese adult.
To make prevent obesity, the height and weight %
should correlate and match,. For example, if a child is only 10% on
height, but the weight is at 25%, the child maybe already overweight,
even though his weight percentiles is near the bottom quarter compared
to the child's peers .
So for our BLUE girl
unless as her height proportionally rises from 75% to 97% thus
matching her weight velocity, she will be at risk for obesity as an adult.
By plotting and looking at her growth
velocity, she should be intervened early to talk about risk of becoming
overweight at age 10.

PURPLE girl:
A quick glance shows this girl's growth started very healthy, growing proportionally 97% for weight and height. As she grows
older, she remains taller than her peers at 97%, but around early as age
11, her weight % has dipped > 2
standard deviations (SDs) or crossing over 2 or more weight curves, now to 75%; and by age 13,
her weight % has dipped > 3 weight curves or SDs, and by age 18 her
weight is only at 25% compared to her starting height of 97%. This is commonly
seen with young ladies who have body morphic disorder often accompanied
by deadly medical condition known as bulimia. She maintains enough
nutrients to still grow tall and thus reaching her genetic potential, but she is far from her ideal weight for her tall stature. Her ideal body weight should be 90 lbs heavier than her
25% weight at age 18! This child should have received intervention
before age 13. If you spot this growing trend in your daughter, call your pediatrician today.
GREEN girl:
She starts her height and weight both at
50%. Around age 10, you can see her weight starts to plateau and few
years later, her height velocity starts to slows down as well. Through
out her adolescent years into adulthood, she gains hardly any weight, and her weight percentile
crosses from 50% to < 3%, and this is also mirrored by her
height which drops from 50% to < 25% when she is 18.
Bulimia can
still present this way, but other
diseases such as cystic fibrosis, celiac disease, growth hormone
deficiency, thyroid problems and autoimmune disorders, infections like
HIV, drug abuse and other chronic illnesses needs to be workedup and
investigated with your pediatrician. 
