Is 2000 Cals a day too much, too little, or just right for a girl who goes to the gym 5 days a week? And by go to the gym I don’t mean walks on the tread mill at low speed for an hour. I mean she deadlifts, benches, squats,etc. plus she’s on her feet 9 hours a day, 5 days a week.
As we’re not a machine that rolls off an assembly line and works exactly the same all the time across everything, we cant really give you an answer to your question.
If she’s been training a while you are better off starting with where she is and making small changes towards whatever goal she has.
If you’re going to go with a big bang change. 2000 is a good a number as any. You then need to modify and adjust based on if she is gaining/losing weight? Does she have energy? Is her training going well or has she hit a wall? Does she wake up wiped out? etc
As you can see, one is a big change followed by a series of little changes. The other is just a series of little changes. At least you dont have a moving target going the second route…