You know - and this is my twopenneth, so feel free to disregard - it just doesn't seem possible to me that having spag bol every day would slow your losses. I think this comes from the same school of thought that having a bar every day slows your losses. It might make a difference the first week you do it - that makes a certain kind of sense, some products make you retain slightly more water than others. But if you carry on doing the same the next week, you'll lose your normal amount of weight (or whatever your brain has decided you'll lose this week - we all know that you just won't lose a steady 3 pounds a week, no matter what you do). It's not like you retain water for every bar or spag bol you eat, each bar or meal making you progressively swell up like a water balloon.
If you enjoy it, eat it. Don't go without in the mistaken belief you can speed weight loss up somehow by not having a particular product. They all have roughly the same amount of calories, give or take 50. It's such a low number of calories overall. Cambridge does put you into ketosis, but that isn't why it works so well - it's because you aren't consuming much food! (It's believed that ketosis is the thing that makes it bearable, sure - but the jury's out on exactly how and why).
This plan is hard enough without putting limits on what you can and can't have. The truth is, we often have absolutely no idea why we can lose 5lbs one week and nothing the next, despite sticking to plan 100%. My theory is it has nothing to do with the type of product you ate - and everything to do with how well you are, what your hormone balance is this week - in short, how well your body dealt with burning your fat in the face of calorie restriction.
