Eating Too Much - Thanksgiving -Health Risks - New York Times

Gorging during the holidays is a bad idea for many reasons.

It can cause "[i]ndigestion, flatulence and... raise the risk for heart attack, gallbladder pain and dangerous drowsiness on the drive home."

In addition, pigging out during the holidays can lead to weight gain averaging a pound, and as much as five pounds or more for the overweight. Unfortunately, the weight gained is rarely lost afterwards.

Since on average adults gain one to two pounds a year, midlife weight gain can be attributed in large part to overeating during the holidays.