I've not heard about the quinine one- our LLC told us that citric acid in diet drinks can disrupt fat metabolism, and bring you out of ketosis. Being a natural skeptic I investigated this and found that citric acid is part of the body's fat metabolism cycle, and so theoretically extra citric acid might interfere with it. I must confess however to have 'cheated' during abstinence by drinking Diet Coke (which has citric acid) and Coke Zero (which doesn't) without any ill effects on my weight loss. I have been convinced now that Diet Coke is not a 'good thing' for various other reasons and so should not be drinking it at all. Lots of other diet drinks contain fruit flavourings and other compounds (such as quinine) that may impact on the diet (although I'd like to see some proof about that).
I do wonder whether LL ban diet drinks so that they can sell their drink flavourings at £9 a go - if they let you drink Diet Coke etc they'd lose out on a chunk of their income...
Their is a lot of controversy about the use of Aspartame in diet drinks - I know Dr Atkins had a thing about this, but LL still use this in the St Clements flavouring- I think the have moved over to Sucralose (aka Splenda) in the Orange and Fruits of the Forest Flavouring.
While I wouldn't recommend cheating with diet drinks, I think that LL's ban on them for knocking you out of ketosis should be taken with a pinch of salt - however there seem to be good enough reasons to avoid them altogether.
The one that convinces me most is that artificial sweeteners of any kind can fool the body into thinking that sugar is on its way causing insulin to be produced, thus making you feel hungry and more likely to eat. But don't take my word for it!
I personally do not think LL would make this up just to get people to buy water flavourings They make more then enough at 66 quid a week!!
Anyone who is doing LL has no doubt tried every other diet, and all diets suggest water be the main source of liquid ingested.
LL is removing us from our addictions, or whatever you want to call it. Diet Drinks are a big part of many who are overwieght. So it made sense to me to cut that out as well.
And I have given it up completely, since I started LL in January 2008. I have not even had one sip, because I am afraid it will trigger the addiction, and from a purely health point of view, diet drinks are equal to poison, so best to just avoid them completely I feel. Or have them now and then, but not one or many a day, ever again.
Of course I don't really know - but I have averaged 4-5lbs weight loss a week for the last 10 weeks - and there doesn't seem to have been any difference in the weeks I drank "diet coke/coke zero" and the weeks I didn't. However the excess caffeine did have undesirable effects! I must say I don't feel it made me hungry but I am sure there is *nothing* good about drinking diet drinks.