Write a discussion in which you explain how you chose an "ideal weight
& an ideal energy intake".

An "ideal weight" is a range which depends on your height, gender, and
bone structure.  There are tables that you can consult readily
available online.  Or you can use the calculator at
http://www.halls.md/ideal-weight/body.htm , which does it for you.

As far as ideal energy intake, this would depend again on your age,
health, gender, current weight, and if you were trying to lose or gain
weight.  Also, if you were pregnant or nursing a baby, this would
require a different energy intake.  So you see, it isn't that "cut and
dried".

If you have questions about your particular situation, the best thing
would be for you to see a nutritionist.  Your doctor can refer you to
a good one.

Hope this was helpful to you!

If you live in the UK , there is a book published every few years by
COMMITTEE ON MEDICAL ASPECTS OF FOOD AND NUTRITION POLICY (COMA)
http://www.doh.gov.uk/coma.htm which regulates the food intake for
each person, useful to look at. bye