Hello,
I'm not sure what this C25K thing is as I fell upon this link through another run that I participated in this past weekend, but the title caught my eye and I wanted to respond.
I hope my story can inspire at least one of you.
I'll keep this story short 
I am a single mom of one teenage boy. I gained a lot of weight during the pregnancy and then never had the will power or desire to work it off. I ended up gaining more over the next 14 years.
I am 5'8" and ended up at 239 pounds. Last year I started a fitness boot camp at the prodding of some of my co-workers. Simply working out did not help my weight as I was still stuffing my face with unhealthy food.
My boot camp instructor talked to me about proper nutrition and it wasn't until then that the weight started coming off.
I changed my eating habits ( I eat all natural and clean now ), started running (baby jogging at first) and I take a boot camp class 5 days a week. I never work out more than one hour a day and I take one day off a week where I relax AND eat whatever I want. 
I have lost 47 pounds since the second week of December of 2009 and I because I'm eating right, drinking lots of water, I dont have all the flabby weight loss skin, etc.
I feel WONDERFUL. Mentally, Physically, Emotionally. I stopped taking my acid reflux medication over a month ago.
You can see my progress at www.sparkpeople.com (free) this is just a place to log food journals, weight, fitness and get support. My screen name there is ITALYNETTE.
I've attached my before and "In progress" photo to this email.
Feel free to email me at Italynette@sbcglobal.net anytime. I'd be happy to share any tips and encouragement with you.
~ Carolyn ~
The Road to Success may be Long and Winding, but the Results are Worth Taking a Tricycle!