This shouldn't change anything to your weight loss as long as you carry on having the shakes. If you feel the diet isn't for you maybe you could just follow the re-feed plan. But you must do a re-feed if you're planning on coming off TFR because this way you won't gain any weight you've lost the past five days.
If you're finding that you don't have much energy. How about splitting up your shakes. So have small shakes throughout the day to keep you going and the extra water won't do any harm as long as it is kept under 3.5L.
Good luck and I hope you're feeling better

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