The pastry-wrapped treats are a festive favourite -- but they're packed with sweet fruits and often laden with fat and sugar.
In fact, a MailOnline audit of 31 popular varieties has revealed that one brand of mince pie is more calorific than two entire McDonald's hamburgers.
Aldi's 'Ultimate All Butter Mince Pie' may come up top in taste tests -- but it is also the most fattening on the market.
The 110g pies, made with Cognac infused mincemeat, deliver a whopping 469 calories -- whereas a McDonald's hamburger is 248 cals.
For context, the average woman is advised to consume around 2,000 calories a day to maintain a healthy weight, while 2,500 is suggested for men.
This means a single Aldi mince pie will eat up a quarter of a woman's daily allowance and a fifth of a man's.
The decadent treats also contain 42g of sugar -- that's the equivalent to 10 teaspoons, over 10g more than is in a Mars Bar.
Adults are advised to have no more than 30g of added sugars a day -- roughly seven teaspoons -- in order to protect their teeth and avoid weight gain.
Mince pies are packed with sweet fruit, spices and wrapped in pastry. But the festive treats are also loaded with fat and sugar.
This website also looked at the nutritional content of mince pies available at Sainsbury's, Tesco, Waitrose, Cook, Marks & Spencer.
The second worst offender from our audit was ready meal company Cook's Mince Pie Crumble Tarts, made with Bramley apple, citrus zest and spiced rum mincemeat.
Each 115g pie contains 465 calories, 32.7g of sugar and 9.5g of saturated fat.
Government guidelines recommend men have no more than 30g of saturated fat per day and women no more than 20g -- meaning eating just two or three mince pies could make you reach your limit.
Too much saturated fat can raise your cholesterol and increase your risk of heart disease the NHS warns.
Mr Kipling All Butter Mince Pies are also among the most calorific at 311 calories per pie, as are the Free From Milk & Gluten Free Mince Pies sold at Waitrose containing 314 calories.
At Marks and Spencer their 'Best Ever Mince Pies' contain 349 calories and Sainsbury's own mince pies contain 243 calories.
MailOnline's audit of more than 30 varieties of mince pies sold on supermarket shelves found Aldi 's 'Ultimate All Butter Mince Pie' (pictured) is the most fattening on the market.
In contrast, Aldi's Specially Selected Millionaire's Crumble Mince Pies, made with caramel and topped with chocolate crumble is surprisingly one of the best mince pies is the least calorific option.
Each 48g pie contains 179 calories -- around the same as two chocolate digestive biscuits.
However, it still contains 18g of sugar and 3.9g of saturated fat.
Eating more calories than you burn will cause you to gain weight over time. Six in 10 adults and four in 10 children are overweight or obese, figures suggest.
Being fat can raise the risk of developing type 2 diabetes, heart disease, cancer and strokes, as well as mental health problems.
'Consistently eating high-sugar treats like these can lead to more dramatic fluctuations in blood sugar spikes and weight gain which can be challenging to shift in the new year,' Rob Hobson, registered nutritionist and author of 'Unprocess Your Family Life' told MailOnline.
But sticking to simpler pies that don't have icing, crumble or puff pastry toppings can help limit calorie and sugar intake, he explained.
He said: 'To enjoy mince pies without overloading on calories and sugar, consider smaller portions or versions without extras like icing, crumble, or cake toppings, which often add unnecessary sweetness and calories.
'Those with thinner pastry may be better choices.
'Mince pies don't need to be off the menu altogether -- they're a festive staple, after all.
'The key is moderation and balance, enjoying them mindfully as part of an overall healthy approach to your celebrations.'
Kim Pearson, a nutritionist who runs a London-based clinic specialising in weight loss, suggests having your mince pie with a balanced meal.
She said: 'If you're treating yourself to a mince pie, it's wise to have it after a balanced meal rather than on an empty stomach.
'The fibre, protein, and healthy fats in your meal can help slow down the absorption of sugar and minimise blood sugar spikes.
'Opting for smaller mince pies or those without toppings like crumble, cake, or icing can reduce the calorie and sugar content while still allowing you to enjoy festive treats in moderation.'