Yes, several times I lost significant weight - always eventually 'crashing out' of the diet and regaining and always being angry and disappointed at myself.
Since then I have studied what your body does in response to big with loss and now I understand why it happened and why the drugs are needed for almost everyone to lose and maintain that loss.
Your body's processes work in a way that fights and then sabotages weight loss, because they evolved at a time when loss of weight normally meant food was scarce and you needed 'help' for it not to kill you.
Your body massively reduces how much leptin it produces. Leptin is what makes you fell satiated after eating. It massively increases ghrelin. Ghrelin is what makes you feel hungry. So the more weight you lose, the hungrier you feel and the less you ever feel like you've eaten enough - even when you've logically eaten enough calories. It changes your insulin pathway so you are driven to eat higher calorie foods than normal. And your brain responds to all this by thinking about food more and more and more. All designed to drive you to go and hunt/gather with more seriousness to overcome the food shortage. But in today's world all instead making dieting harder and harder the longer it goes on and keeping the weight off far harder than weight maintenance would be otherwise.
For some lucky people these processes only persist for a year or two after weight loss (even if you put the weight back on). For others it lasts more years than that.
It's one of the prime reasons the statistics show that the vast majority of people who lose significant weight will out it back on.
Having now read and listened to a range of obesity scientists, they all report the same thing. Losing and maintaining significant weight loss is beyond most people to achieve alone. Some people do it, sure. It's possible that those people had a different cause of obesity than the hormone imbalance that appears to contribute to most obesity and, therefore, it's just that but more possible for them.
I no longer believe it is possible for me without help. I have tried too many times on my own and failed even more. I have lost something g like 400lbs over my adult life - all the same 40-50lbs over and over. I know how to lose weight and can do so - but every diet needs the same. It gets harder and harder and I become aware at the end I am 'white knuckling' it. Until I break and then I gain at an approx rate of 1-2lbs a week until it's all back again. During that time I am driven to eat, eat, eat.
The drugs have changed my life. Totally and utterly changed it and left me capable of making rational choices around food. I am currently 60lbs down and still thinking rationally. I COULD eat plenty of food in day - the drugs don't stop that. But I want to lose weight and so find it possible to choose not to. Left able to make sensible choices, I find I make them pretty well and not only do I eat less to achieve my goal, I also choose differently. No more sugar, no more UPF, no more rubbish. Just whole, healthy foods.