If you are worried about that Labor day barbeque because you are uncertain if you can make a healthy choice ask yourself if you are using this event to predict failure. Be honest with yourself in an effort to recognize the situations and circumstances where you need to retrain yourself. You should take 100% responsibility for your choices.
You can help retrain yourself by repeating certain new habits such as eating slowly. Not only chewing your food slowly but also placing your utensil down between each bite and do not pick it up until you have completely chewed and swallowed each piece. Make a commitment to eat only at the table and do not pick at the food while it's cooking. You can serve yourself on a smaller plate and leave at least a bite of each item on the plate. This will help you train yourself to stop eating when you are full.
Think your choices through. Behavior modification works only if you are consistently repeating new behaviors.