Balancing calories with activity level results in
1. weight gain
2. maintaining weight.
3. weight loss.
4. an eating disorder (i really don't think its 4.. but i had to include it.)

Her parents start noticing changes about her. she's probably just competive though not on drugs

You did not show us the image of the burger, but i shall try to answer as best i can.  when purchasing food, always consider the ingredients as well as the person who prepared it. consider if they were hygienic people or not, in case the burger was infected with bacteria. no mortal should place an infected burger into their mouth.