Its not so much to do with your losses but the bars have more carbs and can stop you getting into ketosis or kick you out, but more importantly the BL bars and Tesco ones are ALMOST the same as Exante ones but theyre not the same. If you have 2 bars and a shake youre not doing Exante, youre not doing any diet as such and you wont be getting all the nutrients you need.
Stick to 2 shakes and a bar - much healthier and youll be in ketosis