It is DEFINITELY best to be open and honest with your treatment team.

I know when I was depressed I lost around 40 pounds- it wasnt deliberate really (though I will admit losing the weight kind of did make me happy- I mean, just because it felt like I guess SOMETHING good that was happening in the midst of all the bad)- so I DO understand losing weight because you jusr dont have the energy, care, or really- capability of taking good care of stuff like that.

But dude, you sound like... it doesnt sound good. If people were to start being concerned about how much weight you have lost- and start getting concerned about the slim fast- would that be a bad thing? Probably not. Those things dont sound healthy... and your health really IS important.

Be honest with your treatment team. Please. Its really for your own benefit that you are. It might be scary- but if you are honest, you can maybe have a discussion with them and figure out what is going on. Its never good to hide things from people who are trting to help you... so please dont. Do it for yourself. Be honest. And talk to them