Re: what does preteens have to eat in order to have an average of 2000 calories

Aloha, Ana,

     Perhaps we should start off directly with my questionning from where 
you received the information about 'exactly 2000 (kilo)calories.'  It is 
totally incorrect, so your source is questionnable, at very best.  There 
is no need for you to be so concerned about your pre-teen daughter eating 
exactly a set amount of kilocalories each day...there is no scientific 
merit to that advice.  As a nutritionist, I teach large sections of 
introductory nutrition here at University of Hawai`i at Manoa, and this is 
just like some questions that I get from my students each semester.

     Now, let's get into some practical reasons why that information just 
can't be true.  People come in all different ages, sizes, shapes, etc.  To 
argue that anyone, regardless of all of those variables, must eat a set 
(and very arbitrary) amount of kilocalorie just doesn't make nutrition 
sense.  The bigger the person, the younger the adult(and, especially for a 
pre-teen who will soon have a tremendous growth spurt to accomplish 
healthfully), the more active the person, the more energy the person will 
need.

     As for your daughter, since I don't have any personal information 
about her (size, degree of development, age, activity), it would be 
difficult for me to estimate her energy needs.  It could be less than 2000 
kcal/day or more than 2000 kcal/day...and her needs probably could vary by 
day, depending on her activity level for the day, at the very least.

     The best way to decide long-term if she is getting enough energy and 
other things like a balance of all the nutrients she needs in her food, is 
to measure her weight and height periodically...and compare those to 
standard charts (probably available from your medical doctor...or from the 
Centers for Disease Control and Prevention in Atlanta, GA).  You can find 
the information directly (I just did) by doing a Google search on 'Centers 
for Disease Control growth charts'...takes you right to the correct page 
which allows you to access the proper growth chart for your daughter.  
These charts were developed for a multi-ethnic population of breast-fed 
babies/children in the U.S., but they should work as an approximation for 
your daughter, too.  If she is growing consistently (for weight and 
height) along a particular percentile line, for her age, and is generally 
healthy, then she's eating just fine.

     A balanced, moderate, and varied diet will do wonders for your 
daughter's growth...and letting her eat foods (aim for less-processed 
ones, for the majority of her food) to satisfy her hunger, not according 
to some arbitrary bit of incorrect advice.  And, not according to someone 
else's idea of what an adult woman's body should eventually look like 
(like in many of the fashion and body-building magazines...these looks are 
not achievable for almost all women without doing dangerous things to 
their bodies).  In addition, any eating style, like the currently popular  
one of 'low carbs,' that restricts/eliminates any nutrient, type of food 
or particular food should also be a warning signal to you that it probably 
isn't correct/safe information for your daugher, for you, or for the rest 
of the family.

     I totally understand your concern about your daughter's needs, 
including kilocalories/day; I have two grown children in their thirties, 
and went through the same sorts of worries throughout their growing.  So, 
I guess my advice to you as a scientist and as a mother, is to 'lighten 
up' just a bit and enjoy your daughter...and allow her to eat and enjoy 
food...not obsess over it.