For me one of the biggest factors in staying on track is perseverance.
Accept that at some point I'll make a mistake. Accept that I can forgive myself for that mistake
immediately, and then move on at the very next choice. If I weren't able to accept this, then any change I made would be moot, because I wouldn't stick with it when I mess up. I'd just say "To heck with it! I'm not perfect so I'll never get this done!" And that's so unfair to myself.
Following accepting that I'm not perfect, and can still make healthy changes was step one.
Step two was deciding on something I knew I could change. I set myself up to succeed. I knew that starting exercise was healthy, but I couldn't ever imagine stepping up on my treadmill for an hour. That seemed so impossible! If I couldn't do an hour I might as well do nothing, right? Wrong.
I knew that I could do 5 minutes. 5 measly minutes a day. So, for one WHOLE month... I walked 5 minutes a day. I even messed THAT up and missed two days. But, I got up the next day and got back on the treadmill for my five minutes. Once again, I had to accept, forgive, and move forward.
At my second month I upped the ante. I made my minimum 10 minutes. I'm doing 10 minutes of movement each day.
As I started to exercise, I wanted to make healthy choices regarding food. I didn't start big. My whole first week I continued to eat as I usually do... the ONLY change I made was to track what I ate. If I wanted a box of Cheez-its...well... that was fine and dandy, but I had to calculate how much that was and write it down. Didn't matter about calories or anything, but I had to start being vigilant.
The second week I realized that I could handle another change. I could start portioning. I wanted those Cheez-its...that's nice, but I had to measure out one serving and write it down. I started naturally aiming towards more fruits and veggies.
I made a huge shopping list. I went food shopping sticking to healthier choices. Making dinner was easier when I had the ingredients on hand.
Lastly, I personally made sticking to my new habits my goal instead of weight loss. Oh, believe me, I want to lose weight. I do. But, eating better, moving more, CONTINUING to follow my plans... the weight will come off eventually. These habits have to continue to be my priority regardless of what the scale says.
It's a reason why I made a little On Plan challenge. I want to focus on how many days I can stick to my plan. Not the scale. If I can make the whole 99 days, awesome for me. If I mess up a couple of times, won't matter....because I know I'll STILL be here after 99 days. And even a couple mistakes don't negate healthy choices.
One small change. Make it a habit. Build it up.
You can do this.