Not to be a grinch about it, but we’re amid the most dangerous six weeks of the year, dietwise. Nutritionists say the average American will gain 5 to 15 pounds between Thanksgiving and New Year’s Day. And before Valentine’s Day, will break his or her resolution to lose it. But with a little care, you can dodge the bullet.

“There’s a lot you can do,” says Sabrina Candelaria, a registered dietitian at the University of Miami School of Medicine. Her advice:

• If you’re a guest, offer to bring a low-calorie dish.

• If you’re the host, offer bubbly instead of high-calorie mixed drinks, or soda water or seltzer instead of soft drinks.

• On the hors d’oeuvres tray, offer celery and carrot sticks as well as cheese balls and bacon-wrapped chicken livers. As an elegant alternative, lay out endive leaves with a little dollop of crab on the ends.

• At dinner, offer low-cal alternatives.

• In cooking, use wine instead of cream in sauces, low-fat yogurt instead of full-fat sour cream in dips, egg whites instead of whole eggs in baking, sugar-free gelatin in the cranberry mold, applesauce for part of the oil in muffins.

• At a buffet, fill your plate moderately and then move over by the potted plant, as far as possible from seconds.

The American Heart Association offers more tips:

• Work on your diet for a few days in advance of the holiday feast.

• Take half a slice of pie — possibly the most-daunting act of human self-denial ever suggested.

• After the meal, take a walk.

In fact, a new University of Exeter study in the journal “Appetite” says a brisk, 15-minute walk before dinner helped reduce cravings for chocolate and other addictive foods.