How long does it actually take to lose fat?

Daily weight swings by one to two kilograms from water, glycogen, salt, gut contents and hormonal cycle. Against a genuine weekly fat loss of half a kilogram, that noise is several times larger than the signal.

Use a weekly average from several morning readings, and judge progress over three to four weeks rather than day to day. The first week typically shows a large drop that is mostly water, and the second week often shows nothing, which is where most people quit.

Fast initial loss, a plateau around weeks two to four, then a steadier decline. Further plateaus follow, usually explained by adaptation and by intake drifting up as vigilance falls rather than by anything mysterious.

Measurements and photographs catch what the scale misses, particularly early on when you are gaining a little muscle while losing fat and the net number barely moves.

Set the timeline from the arithmetic rather than from the event you are aiming at. Ten kilograms is four to five months; twenty is most of a year. Plans built on a faster assumption fail on schedule when reality does not cooperate.

Build in maintenance periods deliberately. A fortnight at maintenance every couple of months makes the whole thing more tolerable and does not meaningfully extend it.