Occasional meal replacenent shakes?

Hi Guys,

Recently I bought the blackmores meal replacement shakes to use for convenience more than anything.

I will sometimes have one per day with some tuna and salad or whatever. I find it convenient sometimes when i'm really busy.

Does anyone ever use meal replacement shakes sometimes and still has had success? As long as i stay at 1200 caloies per day i'm quite happy to incorporate them into my diet as i have variety of other good foods. I don't use them every single day.

Thoughts?

Sorry, the topic is meant to say replacement but i couldn't edit it!