Gaining

For me it was 12lbs

Yeah, absolutely true. I gained 40 or so lbs in a year and didn't get a comment from anyone--I'm 6'2" though and started skinny. If someone shorter gained that much I'm sure they'd get comments.

I can't really say when my co-workers noticed it because I think they're just too polite. By the time my manager mentioned it, I think I had gained about 70 pounds! A couple other co-workers brought up my weight at about the same time.

A friend of mine first mentioned my weight gain at about 50 pounds of gain, but I had not seen her in quite a while. She literally just saw all the gain at once.

My family didn't mention my weight at all, and I think I was up about 60 pounds when I last

Your mileage will definitely vary.