When will they notice?

So far I've lost about 15 pounds (237 this morning!), and nobody's said anything. At what point will my colleagues and immediate family see a difference? It's a pretty large amount of weight, but I've still got so far to go (ideally down to 190). So maybe it really isn't visible yet to anyone but me, standing naked on the scale in the morning. (Now there's a mental image I wouldn't wish on anyone!)

I'm not really bothered by it. I know that it's practically impossible to notice changes in someone you see every day. But I am curious, in an abstract sense, when people I see every day will all of a sudden see me as looking different.