The season of good cheer deserves to also be the season of good news. And boy, have I got good news for you.

The published results of a recent study, led by Prof Dylan Thompson, of the department of health sciences at the University of Bath, seem on the face of it to be something that was most likely nicknamed “The John Belushi Project” by the team involved in the research.

Basically, they got together two groups of fit young men, and invited them to pig out.

One group increased their caloric intake by 50 per cent, while the second group upped the eating and drinking binge by 75 per cent.

Oh, and the dudes were also told that there was no need to walk anywhere, so they were allowed to reduce the number of steps they took on an average day from 10,000 to below 4,000.

So, lots of sedentary action – lots of telly, lots of sitting in front of a nice, toasty fire, lots of gaming. And lots to eat and drink. Lots.

Does this sound familiar? Telly, grub, gaming, nice, toasty fire, another drink before dinner, dear?

It's not really the late John Belushi, and his infamous Animal House behaviour, that we're talking about here. We are talking about all of us, and how we behave at Christmas: too much to eat and drink, and little or no exercise, because we're watching telly and it's cold outside, and who's got the Áine's chocolates?

So, what happens if you do that sort of thing for a week? The researchers at Bath University discovered some startling outcomes.

Partying
After only a week, one group had a significant decline in their blood sugar control.

Their fat cells were over-expressing genes that contribute to unhealthy metabolic changes, and at the same time they were under-expressing genes that are important for our metabolisms to function properly.

Oh dear. And Christmas to New Year is . . . a week. A week of partying and eating and telly and not going anywhere or doing anything much. A week when your blood sugar and your fat cells go berserk.

But, this is a good news piece, remember, and here is the good news.

The two groups of fit young men differed in one regard: one bunch did the bingeing and the sitting around, and the other bunch did the bingeing and sitting around, but also did 45 minutes each day on the treadmill, at a moderately intense pace.

For this second group, there were no negative health consequences.

All the eating and drinking and sitting in front of the fire (apart from the 45-minute workout each day) was cancelled by the exercise.

Their blood sugars were fine, their fat cells didn’t start firing up the bad stuff and cancelling out the good stuff.

And the incredible thing is that this group were the guys who were taking in 75 per cent more calories each day. Even despite out-eating their co-bingers, they had cancelled out any changes from the indulging simply by exercising.

Workout
Now you know exactly why people go for a Christmas morning swim, and for that big post-lunch Christmas day walk. The University of Bath study shows one simple thing: you can do what you like and eat and drink what you like, so long as you also exercise every day.

So, don’t abandon the gym or the walking circuit or the big hike or the workout during the holiday season.

Factor that 5k or that bike ride in at some time during each day, and sail through all those glasses of wine and those roast potatoes slathered in bread sauce.

Chestnut parcels with cider cream sauce
A brilliant vegetarian recipe from Karen Austin, of Lettercollum Kitchen in Clonakilty, west Cork.

The stuffing:
4oz dried chestnuts, soaked overnight
3oz butter
Half pint cider
4oz "instant" couscous
4 fl oz boiling water
2 onions, chopped finely
2 cox's pippin apples, peeled and chopped
3 sticks celery, diced
1 sprig fresh rosemary
salt and black pepper

The pastry:
8 sheets filo pastry
3oz melted butter

The sauce:
4 fl oz cream
Reserved chestnut liquor
Salt and pepper

Soak the chestnuts overnight. The next morning toss the chestnuts in another ounce of butter and pour over the cider. Bring to the boil, then simmer for 30 minutes.

The cooking liquor will be greatly reduced. Strain and reserve the liquor. Chop the chestnuts into small pieces.

Pour the boiling water and 1 oz of the butter, melted, over the couscous. Leave to stand for at least 5 minutes. Melt the third ounce of butter in a small sauté pan and add the onion and celery. Sauté for a few minutes before adding the apple and rosemary.

Toss the mixture together over the heat, then add the couscous and the chestnuts. Season well.

Carefully open the filo and, if necessary, cut according to the size you want to make your parcel. Butter one sheet, lay another sheet on top and butter again.

Then lay the two sheets butter side down and put a good dollop of the chestnut mix in the middle.

Lift each corner of the filo, bring to the centre and twist gently to make a parcel. Bake at 180 degrees for 20-25 minutes until golden.
To make the sauce: Put the cream and the reserved chestnut liquor into a small pan. Bring to the boil and simmer gently for a few minutes. Season with salt and pepper. Pour around the filo parcel and serve.

Sprouts gratin
The best dish of Brussels sprouts you will eat this year, or any other year, is from the late Richard Olney's classic book, Simple French Food. Just leave out the bacon to make the best vegetarian sprouts dish.
60g/2oz lean bacon, cut into half-inch widths
30g/1oz butter
500g/1lb Brussels sprouts, outer leaves removed, parboiled 5 or 6 minutes, drained and coarsely chopped
Sea salt, pepper
15cl/quarter pint double cream
Handful breadcrumbs
Butter (for gratin dish and surface)

Cook the bacon gently in butter until limp but not crisp, add the sprouts, season, and toss over a medium-high flame for a minute.

Spread into a buttered gratin dish, spoon the cream over the surface, sprinkle with breadcrumbs, and distribute paper-thin shavings of butter here and there. Cook for about 25 minutes in a 200°C/400°F oven.

John McKenna is author of The Irish Food Guide; guides.ie