Protien shakes for recovering anorexic 13 year old?

I'm thirteen anda recovering anerexic. My doctor says I need to eat at least 1500 calories a day. That's triple what I used to eat. Would protein shakes and bars be okay to use, even though I'm not bodybuilding? They have lots of calories and since I still wanna eat healthy they still have good ingredients :))) I don't want to get my 1500 a day from greasy unhealthy foods, and protein was something I was somewhat skimping on anyway.