Though estimates vary, on average, people can expect to eat an extra 500 calories a day over the festive season, with some people consuming and extra 3000 - 6000 calories on Christmas day alone. But what the heck its Christmas!
The total expected average weight gain over the holiday period, until the start of the new year, is about 3-5 lb ( 1.5 -2.5 kg).
That's fine. Everyone expects to indulge over the holidays. And everyone expects to be able to shed those few extra pounds in January.
But research has shown that losing the extra pounds does not happen very often. The extra weight gained over the holidays is seldom lost.
Most people consistently weigh more in February - March, each year, than they did the previous September - October.
Of even greater concern, is that most people's weight in March, does not change much over the 6 months till the following September.
The conclusion from this is glaringly obvious - much of the consistent annual gain in weight for most people is caused by the extra calories they consume over the festive season, that is not shed in January! We bare the gifts of Christmas from year to year.
Other studies have shown that the average American today adult weighs 17 lb (8.6kg) more than the average American in the 1970s.
Americans eat more food now than they did in 1970 and the highly processed food eaten has a higher calorie density. That is, There are more calories per serving or food volume.
Researchers claim that to reverse this, people should eat 500 fewer calories each day to bring their weight down. This is equivalent to skipping one meal every day, or fasting for 1-2 days per week. The average male needs around 2500 calories a day and average woman 2000 calories a day. So, 500 calories is about 1/4 of the calories consumed per day in three meals, plus an extra 'meal' for snacks.
Skipping one meal a day will bring the weight back to what it should be. This will offset the extra calories eaten because people each more, and the food is much richer now.
Returning to the weight gained over the holidays. How long will the average person need to diet to shed those extra pounds?
One pound of body fat (500 g) is equal to about 3500 calories.
So if you have a calorie deficit of 500 calories through eating less and exercising more during January you would expect to lose about one pound (500g) per week.
So for a weight gain of 4 lb (2 kg) over the festive season will require you to diet by eating 500 calories less each day for all of January.
In terms of distance walked (calories burnt), an average person will need to walk about 42 miles (67 kg) for each pound of fat. (500g). So for 4 pounds (2 kg) that is 168 miles (270 km).
Running at a slow pace (12 km per hour) requires 30 miles (48 km) to lose one pound of fat, and 120 miles (200 km) to burn off 4 lb (2 kg) of fat.