Dieting Dilemma: When Life Gets in the Way

Life has a way of fouling up our the best laid plans. First you decide to keep your car cleaner, "I'll wash it every Saturday morning." Great, you have a plan. Saturday comes along and someone calls inviting you to go golfing. You think, "I was going to wash the car, but I'll do it when I get back," and off you go. Maybe you do wash the car later that day, but maybe you tell yourself, "I'll wash it next Saturday. It really wasn't that dirty."
Next week Saturday comes along and someone invited you camping so you're in the woods thinking, "Oh, well, I can't wash the car from here, can I?"
Another Saturday rolls around and you've forgotten all about your car washing plan, so even though you're not doing anything else you're thinking, "I don't really FEEL like washing the car right now. I'll do it later," and so it goes.
"Life is what happens while you're busy making other plans." -- John Lennon
It happens to all of us. You join the gym and immediately get the flu. Sign up for a adult education class and you're car breaks down on the first night. When you need to water the grass there's no rain in sight, but wash the car and what happens? These examples aren't meant to give you a pessimistic outlook but instead point out why persistence in the face of obstacles is what separates the haves from the have nots.
It's not what happens but what you DO with what happens that matters.
The best approach is one-day-at-a-time, or even lesser intervals depending on what you are attempting to do. If you're trying to quit smoking, you might want to take things half-an-hour at a time. With food or eating it can be one meal at a time, one hunger pang or craving at a time, or whatever interval works for you.
Choose your Time Interval then Make it Happen
If you say you'll never do something again (smoke, overeat, over drink) it never lasts (you must build in the possibility of occasional lapse), but if you wake up in the morning and decide for that day, and only that day, that you will follow through with your plan, for just that one day, then it can and will happen. There's a real rush of accomplishment when you wake up and realize that yesterday you did it; you accomplished what you set out to do. Each accomplishment make it just that much easier to decide again to follow-through and it gets easier and easier.
Let the successes build, and let the lapses pass. It takes practice to get proficient no matter what you are learning, so plan to persist. Small lapses aren't failures, they are only lapses, and you then decided for the next time period. Doing this allows you to pre-plan when you know you'll not stick to your eating plan, thereby making it okay on occasion to over indulge. Holidays, special occasions. People who maintain a healthy weight do this all the time without thinking. When you give yourself permission to indulge, it's amazing how much less you'll feel like indulging. Take away the forbidden fruit and it's just an apple.