It is to a degree eating less and moving more but you have to get to a place where that feels worth going through, you have to actually want to do it and feel you're worth doing it for. Plus it takes a fucking long time so you have to sustain that motivation and weather through ups and downs, times of stress, all of the usual life stuff that just keeps on going. It's not easy or quick.
I think sometimes people who've never been more than a stone overweight don't understand how big and long and seemingly impossible a journey it is when you're more overweight and how fruitless it can feel at times. Eg. when I was 'overweight' (in my mind) before if I lost half a stone I could see it!
I put on a lot of weight after a major surgery and what I now realise was a major trauma of a freakishly rare health event that should have killed me but luckily I got into theatre just in time. It was major surgery with major recovery time and I now realise major impacts on my mental health too.
Over the last year I've lost about 23lbs. I actually lost a stone and a half through the first lockdown and over the summer then got stuck for September, October and then having to teach through the winter lockdowns, gyms being closed, being stressed and exhausted I managed to put 12lbs back on.
I've lost just over a stone again since February. I don't 'see' much difference. If I was relying on 'looking slimmer' as a motivation I'd be fucked because I'm still bloody fat! That's one of the things people don't get unless they've ever faced down having to lose 4 stone plus. It's a long journey and if you're looking at where you are now and where you want to be it feels ridiculous, impossible, miserable, etc.
To be able to be willing to go on that long hard journey and keep getting back up and back on when you fall off the wagon etc takes a lot. You need the self worth etc to get started but you're gaining it more once you're on that journey and making progress and taking better care of yourself. So you need the spark to start but the journey itself kindles that spark itms? It becomes good in itself, you realise you feel proud of yourself that you went to the gym and stuck at it on the treadmill (even if like me you're only walking uphill whilst your slim friend on the treadmill next to you is running - a nice perk is you're burning way more calories than her anyway because it takes more energy to move a bigger body). You realise your mood is better when you do go than when you don't so when you really don't feel like going next time a voice in you says come on, you rarely 'want' to go but you're always glad you did. Your energy levels start to improve.
You notice you feel better when you don't eat crap and that when you do you feel tired and sluggish and your skin doesn't look good. Or you sleep better or you start doing other things with your time and finding more energy and time in your life because switching up some habits in one area has knock on effects.
I'm still nearly 14 stone. I'm 5'7 so that equates to wearing size 18-20 for me. This is not helped by the fact that unlike those fat celebrities you see who fat seems to spread out over I in fact just develop a massive belly and boobs hanging on the front of me looking like it's been stuck on. I have no idea how to dress! Whenever I look in larger size clothes shop everything is shiny and highly patterned and colourful and just so.not.me.
I've often thought wouldn't it be good if I could just embrace being fat but I can't. I hate that my face and cheekbones and eyes were my best feature but just disappear when I get fat.
Sorry this is a long post and probably not at all helpful but I guess I'm trying to say that losing a lot of weight is a long and challenging journey but that there are multiple rewards in it and once you start it you can start enjoying the journey itself rather than looking at where you want to get to. It kind of doesn't matter where you get to if you're improving your life and your health and feeling better in yourself and still going. I'd like to lose at least another 3stone and that sounds like a crazy amount so I just focus on each day, each week much as I would if I were an alcoholic in AA taking one day at a time.
Don't hate yourself - easy said but honestly I'd look into some metta meditation techniques which focus on directing compassion to yourself and fostering a friendlier, kinder voice in your head that influences how you live and treat yourself and others. Be kind to yourself - it's a skill that can be learned.