According to research from Wren Kitchens, the average Brit will consume nearly 6,000 calories on Christmas day alone. That’s about three days’ worth of food if you’re a woman.
And to burn it all off? It’s thought you’d need to dedicate more than seven hours on the treadmill, 13 hours to aerobics, or walk for more than 21 hours.
But it’s not all bad. While consuming this many calories every day would result in a whopping weight gain of 24 stone in just one year, it’s unlikely that one or two days of indulgence will result in weight gain since significant body fat is gained in weeks and months, rather than hours and days.
What is more likely to occur, however, is a substantial amount of excess gas, a touch of indigestion, bloating, possibly some heartburn and a touch of diarrhoea… (or constipation!)
So how does all this food affect my body?
It will take up to 10 hours to digest your festive eats… here’s how the process works:
After 5 minutes…
Where it all begins! Digestion in the mouth starts pretty much as soon as eating begins. Your salivary glands, teeth and tongue break up food to be swallowed and taken down to the stomach. During this process, food is turned into useful nutrients that the body then uses to burn, grow or store for future use.
After 15 minutes…
Enjoy a tipple with your meal? Alcohol is absorbed within 10 - 15 minutes. Some goes directly to the stomach and the rest to the small intestine which causes blood vessels to dilate, making skin looking flushed.
Meanwhile, your stomach stretches and expands to cope with large amounts of food and produces acid to help break it down.
After 30 minutes…
The sugars in your food cause your pancreas to release insulin, which helps take the glucose released from food into the cells, causing a drop-in blood sugar levels.
Once your stomach reaches peak stretch, two things can happen: vomiting or indigestion/ acid reflux (where the acid from stomach can escape from the stomach and burn the oesophagus lining).
After one hour…
The more you eat, the more blood flows to the digestive tract. To help with digestion, your heart rate and metabolic rate increase, causing a slight increase in body temperature, which may make you sweat and feel tired.
After three hours…
Remember all that turkey you ate? Well, it’s high in protein and fat, which can sit in your stomach for two to three hours before digestion begins, making you feel bloated. And all those sprouts? Well they contain raffinose, an enzyme not well digested by the body, causing flatulence.
Feeling tired yet? That’s because your body needs to concentrate all of its energy on digestions, making most people feel sleepy.
After eight hours…,
It takes anywhere from six to eight hours (depending on how much you’ve eaten!) for food to pass through the stomach and reach the large intestine. During this process, will take in all the nutrients it needs in the form of amino acids, which are absorbed through the small intestine and into the blood.
Having absorbed water and minerals, and stored excess fat, the body will finally start eliminating undigested food as poop.
Does this mean my Christmas dinner is unhealthy?
Contrary to what you might think, a Christmas dinner itself is a fairly healthy affair (though perhaps sans pigs in blankets), explains Haleh Moravej, senior lecturer in nutritional sciences at Manchester Metropolitan University.
“Christmas dinner gets a bad rep but the meal itself isn’t that unhealthy - it’s all the extras that make it so bad”, she says.
“The average person eats around three pieces of vegetables a day, but at Christmas there is so much more variety on offer. [For example] Brussel sprouts - whether you love them or hate them - are really high in antioxidants.
"Beetroot, cabbage, parsnips and so many other greens are also really great options, but these can be made extremely unhealthy by adding duck fat and lard.”