Who doesn't love a seasonal sandwich at Christmastime? Turkey and stuffing, Brie and cranberry - there's always plenty to choose from.

But the festive choices may not be doing your waistline - or the scales - any good.

Food intolerance testing firm YorkTest Laboratories analysed the nutritional content of more than 50 seasonal lunchtime offerings. 

And M&S’ ‘Made Without Wheat Brie & Grape Sandwich’ contains the most fat per 100g - 14.9g - and a whopping 33.5g overall.

The gluten-free lunch contains the same amount of fat as two McDonald’s Bacon and Egg McMuffins.

A host of other Brie sandwiches also make the top 10 ‘worst for you lists’ - even beating snacks full of pigs-in-blankets, gammon and turkey. 

Tesco’s Brie & Cranberry Panini contains more saturated fat and calories per 100g than any other Christmas sandwich.

With 537 calories overall - it packs more heft than a Mcdonald’s Big Mac, which contains 518 calories.

Nutritionist Ali Orr, of YorkTest Laboratories, said: “The results may come as a real surprise to consumers. 

“When you look at the list, you might expect sandwiches containing multiple types of processed meats, stuffing and all the trimmings to be the highest in saturated fat. 

“But what we found was that Brie, made from cow’s milk, is actually the worst culprit, dominating our run-down.

“The meat sandwiches were, however, the most likely to be loaded with salt.”

Other sandwiches highlighted for their saturated fat content are Sainsbury’s Brie & Cranberry Sandwich, M&S’ Smoked Salmon & Cream Cheese Sandwich, Waitrose’s Brie & Cranberry Sandwich and Tesco’s Brie & Cranberry Sandwich. 

Meanwhile Morrisons’ Pigs Under Blankets Sandwich and Morrisons Turkey Lunch Sandwich had the highest salt content. 

Expert Ali says there’s nothing wrong with enjoying a delicious festive treat - as long as it doesn’t become an unhealthy habit.

She added: “People like to make the most of seasonal products because they’re fun and something different. 

“Christmas is also a time of year where you might be forgiven for over-indulging - especially on rich cheeses.

“But it’s important not to make a habit of lunchtimes rich in saturated fats, as they can raise cholesterol levels and may also increase the risk of stroke or heart attack.

"Retailers use the traffic light system to provide guidance on what levels of salt, fat and sugar a product contains.

“Make sure you heed the advice.”

The Wiltshire Gazette and Herald:

SANDWICHES HIGHEST IN FAT OVERALL

1) M&S Made Without Wheat Brie & Grape - 33.5g

2) Asda Triple Turkey Wrap - 31g

3) Tesco Wicked Kitchen Festive Feast Wrap - 27.6g

4) M&S Smoked Salmon & Cream Cheese - 26.2g

5) Sainbury’s Brie & Cranberry - 24.1g

6) Tesco Brie & Cranberry Panini - 23.9g

7) M&S Turkey & Pigs In Blankets - 23.8g

8) Tesco Pigs Under Blankets Sub - 23.7g

9) Waitrose Pigs Under Blankets Sandwich - 23.3g

10 M&S Brie & Grape Sandwich - 21.4g

The Wiltshire Gazette and Herald:

SANDWICHES HIGHEST IN CALORIES OVERALL

1) Asda Triple Turkey Wrap - 777kcal

2) M&S Three Bird Roast Sandwich - 608kcal

3) M&S Made Without Wheat Brie and Grape Sandwich - 603kcal

4) Tesco Wicked Kitchen Festive Feast Wrap 576kcal

5) Tesco Finest Turkey Feast Sandwich - 570kcal

6) Tesco Pigs Under Blankets Sub - 554kcal

7) Tesco Brie & Cranberry Panini - 537kcal

8) M&S Turkey Pigs In Blankets - 535kcal

9) Waitrose Christmas Pigs Under Blankets Sandwich - 534kcal

10) Asda Turkey & Trimmings Sandwich - 530kcal