We're not going to tell anyone not to overindulge because a day of splurging here or there is fun and frankly it's uncelebratory not to.

But what exactly does it do to our innards and how much do we really have to do to compensate for the feasting?

Grab a glass of champers (because let's face it, you might need one to swallow this) and let's take a look.

First the pros:

We can rejoice and be merry that we, of sunshiney Christmases, tend to have a healthier spread than our 'traditional' Christmas counterparts.

We're far more likely to have seafood platters and salads (along with the cheese and mince pies). So bottoms up to that.

Second, we don't want to be Christmas killjoys, so when we're looking at kilojoules consumed, let's be glass half-full about it and come up with celebratory ways to work them off. Like sex, which burns about 1250 kilojoules an hour (and we all have hour long sex sessions, right?). Or the chicken dance, which burns a finger-licking good 2500 kilojoules an hour.

Or you can just go for a jog (five kilometres will burn off about 1105 kilojoules) – and let's face it, there are some freaks among us who find running fun.

Finally, there is goodness to be had in many of our favourite festive foods.

Take the obligatory cheese plate for instance. Organic dairy contains omega-3 fatty acids, which can help alleviate joint pain, boost your mood and lower levels of the kind of fat that causes heart disease.

Seafood is also high in omega-3s, which our bodies need for optimal functioning, as well as other vitamins and minerals. It is also low in kilojoules and fat but high in protein, so it's satiating.

Ham off the bone is healthier than processed ham in the packet and is packed with iron and protein, while  turkey (depending on how you take it) can be a lean meat stuffed with protein and omega-3s.

Add to this spread some green vegies (well, we used to have tinned asparagus as the 'greens' at my gran's Christmas Day lunch, which were really more flaccid, mossy 'browns', but still...), some roast potatoes, which can lower blood pressure and contain fibre in their skin along with a splash of gravy (kidding – there's absolutely nothing healthy in gravy) and Christmas is looking pretty cracking, hold the crackling (there's absolutely nothing healthy in that either).

Or is it.

WHAT HAPPENS WHEN WE OVEREAT?

Our stomachs can hold about one litre, but when we fill them to the brim, it puts pressure on them and the surrounding organs.

Carbonated drinks – beer, champagne, soft drinks, exacerbate this effect because the air fills up more space in our stomachs than the liquid itself. And like there was any more room to fill after the food smorgasbord.

Add to these the excess secretion of stomach acid to break down all the food and it can irritate our belly's lining and can rise up into the oesophagus. Hello, heartburn and dinner repeating itself.

Separate to this, the American Chemical Society explains, the hormones released to remind you that you're full. Really, really full, can make you feel sick.

Now we know, and we've done it anyway, what do we do about it?

Let's just assume for a moment that Christmas lunch or dinner. Christmas lunch AND dinner, will include a pretty spread of leg ham or turkey with cranberry sauce, accompanied by side salads or roast vegetables, cheese and bread, followed by pudding or pavlova,

Pudding AND pavlova.

Here's what you're looking at:

Gobble gobble

85 grams (or a pretty standard serving size) of roast turkey with its skin is about 644 kilojoules.

Whack some gravy on your meat and at about 500 kilojoules a cup, it's about the same number of kilojoules as the meat itself.

All up, that's just shy of a five-kilometre run, followed by a (super) quickie.

Porking

Six slices of leg ham is about 1290 kilojoules.

That's a prescription of one hour of... sex.

Potato

In 100 grams of roast potatoes you are looking at 623 kilojoules. Shake it off with half an hour of shagging.

Drinks

One glass of champagne is about 355 kilojoules.

Naturally, we'll be having six which will fuel us nicely for our 50-odd minutes of chicken dancing.

Seafood

One cup of cooked prawns is just 636 kilojoules but add in a couple of tablespoons of mayonnaise (570 kilojoules) and that's pretty perfectly one hour of sex right there.

Cheese platter

According to Real Simple, the perfect cheese platter includes aged, soft, firm and blue cheeses, with about 115 grams of cheese per person.

Pop some quince paste and and crackers on your plate too and we're looking at about 2234 kilojoules.

For this delicious transgression you shall run for five kilometres,which will warm you up for a steamy sex session lasting just shy of an hour or do the chicken dance for 50 minutes.

OH GOD – and the list keeps going.

Next up is dessert  A small slice of  Christmas cake (50 grams) is 755 kilojoules or a more substantial slice of Christmas pudding (100 grams) is about 1420 kilojoules. We're not even talking brandy butter here. Hmmm brandy butter. Pavlova per slice is about 1369 kilojoules per decadent slice.

That, dear Christmas kin, is starting to hurt our heads. It is also – assuming you have pud AND pav, equivalent to about a 10-kilometre jog (you'll be way too full to run at this point) and about 25 minutes of sex.

And if after all the shagging and jogging and eating and drinking and chicken dancing you don't need a sleep (and a holiday)  then you deserve a drink and for Santa to man-up and do the chicken dance for you.