Just a thought on people not commenting on weight loss- it doesn't mean they haven't noticed.
Personally I would (now) feel uncomfortable saying to someone 'well done on the weight loss, you look great!' as I feel like this suggests they didn't look good (enough) before. Other people's weight is none of my business.
I definitely wouldn't say something to a colleague and perhaps not even to my sister, unless she raised the topic.
I'm early 30s and I appreciate that the body positivity/acceptance culture is a big shift from historic societal norms, and perhaps I'm more exposed to this sort of content than other age groups.
For me, if someone says 'oh Asparagus have you lost weight??' it makes me feel as if they have been sizing me up for being overweight in the past, so the 'compliment' only brings negative thoughts to the front of my mind.
I was really proud of myself for calling my dad out when he recently made a comment about my sister's weight - which is a regular occurrence. He was quite surprised but I hope that has given him something to think about as to one of the reasons his daughters haven't felt loved, cherished, and empowered their whole lives.
Or maybe I'm just a snowflake millennial...