Won't listen to someone that is thin

They're usually looking for a 'secret'-as in one that will allow them to not actually change anything and give them results. I've been guilty of this (scrolling through weight loss searches on google, reading health and fitness magazines making unrealistic promises on the cover). Change is hard. And accepting the idea that change is actually needed is hard.
I'm under the belief that most people KNOW how to lose weight-its the matter of doing what needs to be done.

I'm still very much overweight, but I've been successful at losing weight in the past, and I've lost almost 40lbs now. My friends all have had weight issues, many of them topping 300lbs, a couple 400lbs. Some of them have successfully lost significant weight without "trying" (they joined a sport, started a new medication, or became depressed, etc) but regained it. None of my friends are interested in what I have to say about CICO or how to weigh food, or trying new workouts...What I do, is I first invite them to do an activity, a walk or swimming, or something active, once we are doing something, then I solidly identify myself with them- "I'm fat, being fat sucks, I'm right there with you" (in your case, maybe you can reflect on being overweight, and say mentally you're with them) and then work in some sage advice I've learned, and try to finish with something like "It's pretty unlikely that you or I will ever work out or eat a healthy meal and say 'I regret doing that' - there's nothing to hate about it."

Last night I excitedly told a friend (who wishes she could lose weight) about a 30day challenge I joined, I showed her the calendar, but I said "I don't know how to do a plank, can you show me?" and she more or less did without really doing one but I practiced planks and a few burpees (which she had never done) to sort of raise the mood. Talk is cheap! I'm hoping I can really engage my friends by sensitive-but-in-your-face example.

Even as I get compliments on my weight loss, I run into people unwilling to listen. I cannot tell you how many times people in my office have done "detoxes" or "cleanses" and then wondered why the weight came back a week later. And yet, they continually embark on new nonsense quests with more "detoxes" and "cleanses" as if somehow, the 4th (or 10th) time is going to work, when the first three (or nine) didn't. (I'll admit to being unsuccessful at losing weight quite a few times, but when I *was* successful it was because I changed something in my approach. This time it was using MFP. I had never actually counted calories before.)

I flat out tell the detox crew they're wasting their time and give reasons why and it doesn't penetrate their skulls. I tell them I have lost more than 40 pounds this year and I never once spent a week being miserable while drinking only some silly $10 a bottle juice. I continually recommend this site to folks but I am not sure any of them have signed up yet.

I once had a coworker tell me she tried counting calories once but she found she was only eating 1000 calories per day so that wasn't possibly her issue. (I refrained from telling her that she was surely counting incorrectly, based on her current body size, if all she came up with was 1000...)

I imagine I am getting ruder and snarkier about this every time the topic comes up in the office, so mostly I just keep my mouth shut these days.