By 2003 (I was about 19-20), I was 160lbs at 5'5. I was on the fast food diet - I ate nothing but crap! It was terrible! I was so weak and flabby.
I decided to change. I lost weight over one year by eating healthy and counting calories, going to about 116-118lbs at 5'5.
In around 2005, I decided that being skinny and unfit wasn't all that great either, so I started weight lifting. Fast forward now to 2010, and I have put on a good amount of muscle mass (normally 123lbs). Of course, I'm pregnant now so I'm 134lbs at 20 weeks, but my baby weight doesn't count right now.
OH and I both work in a police department and fitness is a major point in our life - in fact, it's how we met!
I will never go back to being lazy and consuming crap food! I can't even stomach it anymore except the occasional pregnancy freakout.
My only advice is this-
It takes effort and dedication to lose weight and keep it off! Losing weight is the easier part - remaining on plan for the rest of your life is the most difficult. Your body was not meant to process crap processed foods - eat fresh greens and eat a fresh wild salmon!
Diets do not work. Diet pills do not work. ONLY a lifestyle change works. If losing weight, getting fit, and keeping that way was so easy, everyone would be fit and healthy. It takes work. When you are ready to work at it, results will come.