The holidays are a difficult time to maintain a diet to lose weight, but there are some tricks to keep it together. The following are three methods to create a plan so that when you do go to holiday celebrations, they don't destroy your progress and get you off track.
The hardcore method
You stick to your exact same diet. You count your calories. You probably don't eat stuffing or cake or drink alcohol. This method requires an understanding family and extreme determination. If you have great impulse control and look at a donut and think "I don't need that" and you don't eat it, this might be a good option for you. This method does not require any prior planning, except maybe gearing up for understanding portions and how many calories might be in a dish. Be careful of that though. If you haven't been measuring your food for a while (with a scale or volume measurements) you will likely underestimate calories.
Benefits: your diet doesn't change at all, and you keep making progress. There is total consistency and zero compromise.
Disadvantages: the same as trying to lose weight in the first place, but now with the added sting of temptation everywhere.
The "screw it" method
You may be the type who enjoys the holidays; the opportunity to indulge a little, enjoy time with the people you love and do some things you don't get to do often. That's fine. There's nothing wrong or shameful about that, but having a plan will help you a lot going into it. The best way to do this method is to simply say to yourself "I'm on a short break for Thanksgiving. Wednesday through Saturday, I'm not going to count calories or feel bad about what I eat or drink." The important part is what you must think to yourself after that: "on Sunday, I'm going to go back to my diet and continue doing what I need to do to lose weight." Having a plan will allow you to take a break, but get back on the horse even if the process is only as long as you writing down or saying out loud your plan.
Benefits: you enjoy the holidays, don't have to worry about your diet, and you get a nice break from the grueling process of trying to lose weight.
Disadvantages: you'll probably regress weight loss progress. When you get back to your diet, you will be disheartened by the regression of progress, but with a plan in place, it will be better than otherwise.
The "enjoy but don't overdo" method
This is a mix of the two previous methods and is the hardest depending on your personality. Basically, you enjoy the food, you don't count calories or really restrict yourself, but you also don't go overboard. You stick to key weight loss principles like eating lean meats before you eat any filler (like stuffing or bread) or dessert. Keep it simple and eat slowly until you feel satisfied, but not more than that. One of my biggest recommendations is that if you like to drink, choose mixed drinks with liquor and few sugary additions. Personally, I usually drink Manhattans or White Russians, but if I'm trying to lose weight, I'll just sip straight whiskey. Also, make sure your hunger is satisfied before you drink.
Benefits: you can enjoy the food and drink associated with the holidays, and you don't have to explain to your potentially not so understanding kids or siblings that you're specifically not eating as much on purpose.
Disadvantages: you're not going to make as much progress during the holiday and this method is hard to stick to. This method is especially difficult if you have poor impulse control and have a hard time not "just having one more."
Keep in mind that you don't have to pick just one of these for the entire holiday season. Maybe you try all three and see what works. For Thanksgiving, you do the hardcore method. For Christmas, you try the "screw it" method, and for New Year's, you try the "enjoy but don't indulge" method. Each method will work with varying success for different people, but in general, some of them tend to work better for certain celebrations. Long celebrations tend to work best with the hardcore or "enjoy, but don't indulge" methods. Shorter celebrations generally work better with the "screw it" method.
The most important thing to remember is the cardinal rule of losing weight: don't give up. Talk to any ex-smoker, and ask them how many times it took them to quit for good. It's highly unlikely they'll say "once." You have to keep at it and learn from your mistakes.
Email or call me anytime, and I'll be more than happy to give you advice and answer any questions you might have at no cost. I want to help you achieve your fitness goals, and a conversation over the phone or through the internet is something I'm more than willing to do to help someone make their life better.