From the Shangri-La Diet forums:
This is week 5 for me, and I have lost 7 pounds so far.
I am a 37 year old mother of two — 5′6″ and started at 191 — the heaviest I have ever been in my non-pregnant life, with a BMI that fell in the “obese” category. I heard about Shangri-La from another woman, whom I dislike. I thought the whole thing sounded ridiculous, so I set out to prove her wrong. I replaced the two sodas I used to drink each day with two cups of sugar water, each 12 oz and 140 calories, exactly the same as the soda. This meant I was not changing my diet at all (other than removing the caffeine, sodium, colors and flavoring in the soda). I didn’t purposely reduce my calorie intake, and I didn’t change my exercise habits.
I’m amazed at the results. I’m much less hungry. I don’t crave sweets or soda (the way I have my entire life) — in fact, I haven’t had a soda in weeks now and I don’t miss it. I’m eating a reasonable portion size at meals and it’s easy.
It is an experimenter’s dream, by the way, to produce a big effect with tiny change, and a theorist’s dream to have a counter-intuitive prediction confirmed.
It doesn't seem like all that much - it may be possible that this lady ( and congratulations to her for deciding to make changes ) made this one change and didn't make any other ones, consciously or not, to her diet or exercise regimen, but unlikely.