I am no dietician, however, I have done many ultra marathons!
And Physio bot - let me assure you, 17g of protein from a Shake is not going to contribute to the mainteance of muscle mass during a detox and a massive calorie deficit.
Starvation leads to a loss of fat, yes, but also lean muscle, organ tissue, the body reacts by looking to retain mass, via collareral fattening, thus increasing appetite, which is supressed with thermogenic tablets, which in turn causes increased fat loss, which ..... etc etc
Like I said, I am no dietician, however, having fuelled myself through many calorie deficit runs, the plan looks dangerous, and I can not believe that there is no mandatory GP consulation warning on it.