No appetite while training

I read a post on here last night and wanted to come back to it. Now there are too many to search through. I'm currently a healthy weight and looking to just firm up. Maybe drop 10 pounds at most. Since I started training daily I have little to no appetite. I don't drink anything other than water or coffee on a normal day. I have never been a snacker. Now I think the extra calories are crucial so my body isn't like "whats going on?!?) I burn an average of 600 calories a day and sometimes have to eat when I absolutely do not want to just to get some extra calories to meet the minimum1200-1360 I am supposed to before exercise. Any suggestions? I am thinking maybe protein shakes to fill the void.