Fitness

When we're at our biggest, our skin holds everything "up." When there's less everything to hold, our skin sags lower due to gravity and our fat hangs a bit lower. This is why the spare tire "collects" around the lower part of the abdomen when everything used to hang higher when we were at our biggest weight.

You probably have lost some girth there in the middle. Try your non-stretchy pants that you used to wear for formal occasions and see if they fit any differently now that you have lost 4 kg. Or, an old leather belt with well-worn belt holes can show progress because we're suddenly needing the next smallest hole to hold our pants up.