We've had a few weight loss threads on this site, especially for people trying to improve themselves. I figured sharing my personal experience may be helpful. If not, this is my bragging thread.
I was pretty typical in letting myself go. I work about 60 hours a week, have an active social life (that includes a lot of calories from alcohol and bar food) - so I had no idea how in the world to do all that and not look like a Teletubby.
First thing I did was head to the doctor. It really helped gain me perspective, with all the diet plans out there - in what works and what doesn't. For example, the typical is "exercise more". The problem is that cardio workouts (which are the most effective calorie shredders) just won't work long-term for me, since I hate running and most cardio workouts. I did start playing baseball, which helps, but isn't going to burn a ton long-term.
I started an anerobic program, which helps me lose some of the fat and build more muscle, but that's not enough.
So, it was time to take a long, hard look at what I was taking in. I created a spreadsheet (warning: nerdery!) and forced myself to enter every single thing I ate, calorie content and protein content. Even if I binged, went out to eat, etc. - it went on the spreadsheet. It's much easier to keep yourself responsible when you have to own up to being bad. I also entered any exercise that occurred.
Once a week, I would weigh myself and mark that down as well. Over time, it was good to see how eating fewer calories and doing moderate workouts made a difference. If I had a bad week, my weight would show it. It became a huge motivating factor when I could correlate those.
Why protein? We've always heard it makes you fuller. In practice, that's absolutely true. Days I ate more than 80 grams of protein actually showed fewer calories overall than days I didn't.
The hard part about this is obviously the time commitment. You have to look up every single thing you eat - but that becomes another motivating factor. I went from eating 60 calorie/slice wheat bread to 35 calorie/slice. I went from whole milk cheese to skim milk. I can now make a sandwich, with light mayo and cheese - for under 130 calories. That's insane. You start to pick up on some of that stuff you can do if you pay close attention, which this method forced me to do.
Oh yeah - results. Obviously, I lost 45 lbs in 5 months. That's probably a bit more than a normal person should, but it's definitely doable. I've now bought a wardrobe that's actually stylish and fits. Not only do women look at me much differently (I've caught three different women check me out at work today), it actually helps in every aspect of my life. People really do treat you better, I got the promotion at work I was looking for, and have generally been more confident than I've ever been.
I'm obviously proud of this - but this is something anyone can do. Find out what works for you, and get it done. You won't be sorry.