It seems to be more complicated (or unpredictable?) than that:
> In this study, rapid weight loss was associated with the loss of kidney function in males with normal weight, and with improvement of kidney function in overweight males.
> Our study showed that BMI and BMI change were not associated with eGFR change in females.
Your internal organs can't keep up with that kind of mass fluctuation, for one. Keep an eye on your kidneys.
It seems to be more complicated (or unpredictable?) than that:
> In this study, rapid weight loss was associated with the loss of kidney function in males with normal weight, and with improvement of kidney function in overweight males.
> Our study showed that BMI and BMI change were not associated with eGFR change in females.
https://pmc.ncbi.nlm.nih.gov/articles/PMC4658128/