Why is she even looking

My daughter, is really trying my patience.  As she graduated high school, has her first job, just had to have her new cell phone now and it took almost every dime she had in the bank to get it, and her need to buy clothes.  But I have been watching her lately and she isn’t eating right.  I happened to walk into her room last night and seen she was searching the web for weight loss pills.  Why does she feel she needs to weigh less?  She doesn’t have a weight issue, she isn’t over weight.  I notice now that she is working, she isn’t eating like she should.  So last night she complained she isn’t feeling well.  Well she needs to eat more.  So I hope this weekend I get some time to sit down and talk to her.