From mince pies to ham and the glut of Christmas drinks and parties, it's easy to gain weight over the silly season.
But just how much can the average person expect to pack on, and which foods are the real culprits to be cursing as we squeeze into our togs?
Nutrition lecturer at the University of New South Wales, Rebecca Charlotte Reynolds, shares her findings and top tips for keeping trim.
During the holidays, we're out of synch with our normal routine, which can encourage change in body weight.
While studies around fat changes over Christmas are few, those that have been conducted reveal a mixture of results.
A 2009 American study of 195 adults monitored over a six week Christmas break showed an average weight gain of just .37 kilograms.
Another smaller study of 26 British adults over a two-week Christmas period found they gained an average of one kilogram. The maximum weight gain in the group was 4.4 kilograms.
When it came to obese adults, a Swedish study reported highly variable changes in weight from a gain of 6.1 kilograms to a loss of 8.8.
An American study also found obese students assessed over Thanksgiving gained an average of 2.2 kilograms while those with a normal BMI added just .2 kilograms to their waistlines.
Some studies have found no weight gain over the holidays, but an increase in body fat.
Factors which contribute to weight gain in general were sited in a large study of 120,000 American adults over a four-year period.
Potato chips, potatoes, sugary drinks and both unprocessed and processed red meats were noted as being major contributors. Coupled with hangovers and changes to sleep, for many, these factors are amplified over the Christmas period.
Five tips for avoiding a Santa belly
1. Choose foods associated with healthier body weights
> Salads over white bread
> Oat slices or biscuits over shortbread biscuits
> Roasted nuts over potato chips
> Turkey or chicken breast over salami
> Shrimps, prawns and other seafood over sausages
2. Eat intuitively
Try to listen to your hunger and fullness. This will help with the feeling of sickness that can come at the end of Christmas day due to over eating.
Choose smaller plates, as these are associated with reduced food intake compared to larger plates - even if you have a level of intuitive eating.
Put a smaller variety of foods on your (smaller) plate - and don't go back for seconds. If you have a large variety of foods, you are more likely to eat more - something called sensory-specific satiety.
One study reported that systematically recording what you eat, drink and how much you move during holiday periods was associated with improved weight.
Use goal-setting and self-monitoring sheets or apps to help regulate the amount of alcohol or potato chips you consume each day.
4. Get outside
Go for walks or swims and try to avoid binge-watching television on your days off.
5. Avoid soft drinks and excessive alcohol
When you do drink alcohol, choose a soda mixer with a piece of fresh lime to have with your spirits and drink water in between each alcoholic drink.