According to the American Council on Exercise, an average Thanksgiving meal is about 3,000 calories and 29 grams of fat.
"Many people start by snacking throughout the day and that combined with the meal can lead to a total caloric intake of 4,500" said Cedric Bryant, the council's chief exercise physiologist.
Remember that 3,500 calories is equivalent to one pound of body fat. "A 160-pound person would have to run at a moderate pace for four hours, swim for five hours or walk 30 miles to burn off a 3,000-calorie Thanksgiving Day meal," Bryant said.
Other than eating calories, many people tend to drink the calories with fancy holiday beverages.
A 16-ounce peppermint mocha from Starbucks with 2 percent milk, for example, contains 400 calories, 15 grams of fat and 49 grams of sugar. One eight-ounce glass of eggnog runs 160-290 calories. Add a shot of liquor and that tacks on another 60 calories.
These holiday beverages can be equivalent to a meal. If added to a 1,800- to 2,000-calorie day of food, weight gain is inevitable.
Many people may not realize that over the course of one decade, the average adult consumes 10 million calories. In order to have no change in weight throughout the course of the decade, a person's food intake must very closely match energy output, so there isn't much room for error in the eating department.
If people consistently eat "a little more" on a daily or monthly basis, they are setting themselves up for weight gain.
Holiday meals are delicious, but some people ingest holiday meals to the point of stomach pain or difficulty breathing. The digestive system has to work extra hard to process an "unsettled stomach".
Heartburn is a result of eating too quickly or overeating. Heartburn occurs when the valve of the esophagus and stomach are weakened, allowing stomach acid to rise upward.
An effective way to balance a holiday meal is to fill half the plate with vegetables and/or fruits, one quarter carbohydrates and one quarter meat or meat substitute.
A serving of meat should be equivalent to the size and thickness of a deck of cards, and carbohydrates should be equivalent to the size of a fist. Creating smaller portions results in healthy digestion and caloric consumption.
It is challenging to control portion sizes, but only self-discipline will result in healthy eating. People commonly skip workouts to attend holiday parties, so self-control is needed.
Incorporating physical fitness -- a recommended 250 to 300 minutes a week -- is vital to weight maintenance.
Diet and exercise can't be stressed enough here.
Staying trim and slim throughout the holidays requires portion control and physical activity. Some people might be tempted to use weight-loss pills, but these have risks unlikely to be encountered through a healthy lifestyle.
Elizabeth Kovar has been working in the fitness industry since 2006 with international experience from India and Australia. She has a master's degree in recreation and tourism and is the Wellness Center director at the YMCA. She can be reached at email@example.com.