Models are always approximations; they are never spot on but will get you in the ballpark. Even if calories isn't perfect it still reinforces the notion that reducing your intake will reduce your weight gain.
There is no Batman if there is no night time.
"I am the damp-dreary-overcast-day!"
The ideal voice for radio may be defined as showing no substance, no sex, no owner, and a message of importance for every housewife. -- Harry V. Wade