okay, i have these Kirkland signature "weight loss shake"'s at home that my mom bought for herself.

i'm trying to bulk (keep reading) and i'm planning on drinking post-work out shakes after i do some research on which one would be good. but my main question is:

is there anything in these weight loss shakes that cause you to lose weight...or is it just supposed to be a shake with vitamins and minerals (so it acts like a full meal)?

cuz...i know you're supposed to replace meals with these things - if you want to LOSE weight - but what if i wanted to gain weight? could i just drink these during the day (or maybe just save one for after each workout) and use that to help me gain weight?

and yes...i do know the main way to bulk is to eat eat eat! i'm already doing that. all opinions appreciated, thanks in advance!