I don't mean to be controversial here - but the cambridge shakes contain protein + sugar (12.8g per shake, apparently). I honestly don't see the difference between that and drinking protein shakes - especially if she's eating veggies/meat and milk alongside - she'll be getting enough carbohydrates, and not in the form of sugar either. That's a good thing. I certainly don't see any difference between that and slimfast, which is two shakes a day plus a meal. I know that cambridge is finely balanced etc etc but all it is, is a protein shake with sugar and flavourings and vitamins too. They dont even contain any huge amount of fibre. I'm not recommending she does this, I'm just saying that from a medical standpoint, it's the same. There's even a bit of fat and some carbs in protein shakes.
See:
Calories in Designer - Designer Whey Instant Shake Mix Chocolate
I also don't get why people say that the cambridge shakes are perfectly balanced when they don't contain enough protein. I started at 73.8kg, and would be advised to take 3 shakes a day. My book (and the newest guildlines) state that 0.8g/kilo bodyweight is the minimum for HEALTHY people. Most overweight people aren't all that healthy with additional problems because of thier weight, but we'll ignore that. That would give me a requirement of 59g protein per day. 3 shakes contain only 43g. I wasn't even that overweight to start with, so it's even worse for people who start heavier. Now I'm down to 8st 11ish, and even now my protein requirements are 44g.
sorry if I sound like I am harping on, I think the cambridge shakes are a great product, and probably contain enough protein to stave off serious atrophy. But they are not perfectly balanced.
Sorry again, I don't mean to rant
Lots of Love
Ida xx
Edit: just wanted to say that I am not a qualified doctor. I am a medical student, (as mentioned) and chuckie should therefore take what I say with a pinch of salt. I am not a cambridge diet counsellor either, but nutrition is a field that I am very involved in.