i'm with sox.. they're meal replacments up to a point. I down my ALN nitrean shakes for breakfast in the morning, eat a meal, then go on with my day taking the shakes post workout and before bed.
Make sure it's not your sole source of protien.. if it is, when you eat other sources your body will reject them i.e. upset stomach because your bacteria in yoru GI track has adapted to taking in that one particular source. FOOD should be your main source of everything..supplements are just that..supplements to what you're already doing.