This isn't part of my 'diet' but it's a HUGE part of my workout. I drink one about 30 minutes before I workout. It really helps with my stamina. There have been times that I've worked out so hard that I get the shakes - do you know what I'm talking about?? If you drink this - you won't get the shakes! I'm sure any protein powder mix will do - I got this at - you guessed it - Costco.