I know a lot of people on here may disagree but i have found that using a heart monitor to control my runs has helped me a lot.
I found running to a specific pulse range really helped me to control my pace. I also found downloading a free running app in my case Endomondo really helped by letting me see exactly what distance i was running, it also allows me to study my improvemnet over time and to enter comments so acts as my running diary.
My sister is massively overweight. At a recent family meal we all sat down in a restuarant and order our meal. I had my usual STaeak and Chips with peppercorn sauce, she spent 5 minutes talking to the waitress telling her how she wanted her chicken and potatoes cooked without skin and butter so she ended up with what looked the most bland meal i have ever seen. She then sat there looking pleased as punch with herself. After the main course we decided to not have desert apart from my sister who had one of the largest ice creams with chocoalte and marshmellows and sauce all over it. She couldn't see that she was wasting her time pretending to eat healthy.