No, someone told me that the only way for me to be able to go back to the weight I was before is by dieting and not exercising.
and yet you listen to them and clearly ignore the hundreds of posts on your thread....
I'll be blunt - the person you spoke to was a moron - or at least didn't have the first idea about what they were talking about.
IT'S VERY SIMPLE
if you run a calorie deficit you will lose weight i.e. take in less calories than you can burn off.
So if you eat 20,000 calories a day, you'll still lose weight if you burn off 20,001....albeit slowly.
1lb of fat is equilvelent to 3500 calories therefore to lose 1lb you need to have a defecit of 3500 calories - this isn't an exact science either as you could say "well I won't eat for a day - will I lose weight?" the best way to lose weight sustainably is SLOWLY. 1-2lb a week is considered a safe long term effort.
But losing WEIGHT is daft, you want to lose FAT - in order to do this you need to ensure you take in enough protein to feed muscle and lower calories to lose the flubber. So what you eat to fulfil your calorie intake is important. You need energy to work, you need to work to lose weight and build lean muscle mass.
Cycling is FANTASTIC for burning fat as you will inevitably cycle for a decent amount of time in a good heart rate zone and burn more calories than doing 5 pressups for example. HOWEVER, you're not getting a 6 pack cycling - well not a defined one anyway. So adding strength and conditioning to your training is of course important. A simple 5x5 strongman routine would be a good start....google it.
alot of this stuff above is VERY basic, a trained professional would be able to advice better (which I am not - I did study gym instruction which covered the basics but I did it for interest rather than a career)
to be honest, if you went to ANY gym, got them to put together a workout plan it would cover everything you need - you'd just need to stick to it.
I'd also highly recommed kettlebells, great for stamina and definition of muscles.
But largely alot of what I said above has been covered in the thread before - if you're going to ignore it and follow the advice of someone who purely wants you to diet then goodluck to you.... you'll lose weight for sure, but you'll more than likely lose muscle mass too and be as weak as anything.
Oh and additionally, ignore BMI completely. Get a cheap set of scales with Body fat on them (£30 on amazon) they will assess your body composition, this is what you should be paying attention to, make the numbers against Bodyfat go down and the muscle mass go up and you're fine