This gets cited here weekly, usually second-hand, so it is worth setting out what it does and does not establish.
FLOW is the relevant trial and it reported a meaningful reduction in kidney-disease progression and related death in people with type 2 diabetes and chronic kidney disease. The mechanism looks to be a mixture of reduced albuminuria, better glycaemia and blood pressure, and a probable direct anti-inflammatory effect on the glomerulus. Separately, eGFR is genuinely noisy during rapid weight loss — a small early dip is common and usually haemodynamic rather than damage.
Where I think it is weakest: the subgroup findings are the part I trust least — with enough subgroups something is always significant, and these were not all pre-registered.
So the question, as narrowly as I can put it: how to read eGFR during rapid weight loss, given that creatinine depends on muscle mass and muscle mass is changing. Practical detail welcome, however dull — the duller the better.
Note on sourcing:
Figures above are from the primary publication rather than the press summary. If a number here disagrees with one you have, post yours and we will work out which of us is reading a secondary source.