This works much better, she said, than telling them you have to cut back. That's an invitation for them to come back with tough-to-resist lines such as "Oh, it's only one day," or "You can afford it."
If you still experience resistance, tell your hostess: "I'd love to take some home for later." Redfern added: "They don't need to know if you actually eat it."
But if you don't want that temptation -- the pumpkin pie calling from the kitchen at midnight -- learn to be firm and repetitive as a guest, Redfern said.
''It almost takes three times for them to get the message," she said. So, repeat, repeat, repeat, cheerfully but firmly.
There's more on healthy holiday eating at the American Dietetic Association.
SOURCES: Julie Redfern, R.D, manager, Nutrition Consult Services, Brigham and Women's Hospital, Boston; Connie Diekman, R.D., director, university nutrition, Washington University, St. Louis