There are 6 milliion Americans with Type II Diabetes who don't know it. A heavy meal could be a deadly curse. If you are over 40, obese, lead a sedentary life style, or have a family history of diabetes, you could be at increased risk. See your physician and ask to be checked for diabetes.
Enjoy your Thanksgiving meal in moderation with portion control. If you have many items on your menu and several different desserts to choose from, have some of each, but in smalll portions. Consider eating less at earlier meals to keep your total calorie intake for the day under control, but don't skip a meal.
If you're the cook... consider using lower fat and sugar alternatives to your recipes, and ask your helpers to do likewise.
Consider a walk after dinner instead of plopping down in front of the TV immediately.
Over the next few weeks of the holiday season, do your best to not pack on the pounds. Enjoy in small portions.