First of all, it's not simply not eating but drinking water. You can understand it as a way of life, which most ordinary people can't do

Secondly, reducing fat is feasible, but individual pertinence should be considered.

Third, your understanding of the valley is only at the stage of asking questions here, and you have no conditions to do it well.

Conclusion: For you, drinking water alone is not enough, and your body will have problems.