Biggest Loser Challenge

As soon as I finished a 3 week Biggest Loser contest, I decided to join another one with about 8 other people. You would think this would motivate me to lose weight, eat healthy and go to the gym. I've been working out but when I try to eat healthy, I fall off the wagon! Today for example, I started the day out right with a healthy breakfast and I brought a healthy sandwich for lunch. As I get to work I notice the mini donuts sitting in the hallway and tell myself I'm not going to eat them. Sure enough I have had about 4 of them and now I feel guilty! It's always hard for me to stay on track on the weekends for eating healthy. I need some motivation! I have a day and a half until my next weigh-in so hopefully I'll get back to eating veggies.