They are touted as a healthy alternative to traditional meat patties.
Yet some vegan burgers contain up to 10 times the amount of saturated fats found in their carnivore-friendly counterparts.
The shock discovery undermines the purported benefits of a plant-based diet and runs contrary to advice from NHS England, which urges people to avoid the cholesterol-raising fats.
Frequently found in butter, lard and cheeses, saturated fat is closely linked to an increased risk of heart and circulatory disease.
According to a report by The Mirror, one of the worst offenders is The Moving Mountains B12 burger, sold at Marston’s pubs and other outlets.
That alone has 20g saturated fat when uncooked – a woman's entire recommended daily limit and two-thirds of a man's 30g.
The Meat Free Butcher burger, sold by Aldi, contains 15g of saturated fat in each portion. That's 75 per cent of a woman's daily allowance.
Tesco's Beyond Burger, which is also available at All Bar One, fares slightly better with 5g saturated fat, but this is still more than leading meat versions.
In comparison, a McDonald's Big Mac – one of the chain's most popular products – contains 9.5g, while their classic hamburger has just 3.3g.
The Bird's Eye Original Beef Burger has just 2.7grams.
Meanwhile, the No Bull vegan burger, from Iceland, contains 1.6g saturated fat but also packs 5.8g of sugar – one sixth of the 37.5g recommended daily allowance.
One explanation for the high saturated fat content in vegan food is the use of coconut oils, which are renowned for being fatty.
Fortunately, the quantity that's present often reduces when cooked.
Simeon Van der Molen, CEO of Moving Mountains told MailOnline: 'The nutritional information for the Big Mac is based on cooked nutritionals whereas those for the Moving Mountains burger are raw nutritionals.
'Cooked nutritionals will always have less fat content than raw nutritional values as it doesn’t take into account the changes to fat content during the cooking process and the majority of fat that is drained away during this time – therefore the comparison of saturated fat content between cooked and raw nutritionals is completely inaccurate.'
Fiona Hunter, Nutritionist at Healthspan, told MailOnline: 'The results are quite shocking but not surprising because a lot of ready prepared vegan foods use coconut oil which is high in saturated fat.
'Saturated fat can increase cholesterol which in return raises the risk of heart disease.
'People often assume that vegetarian and vegan foods are automatically healthier, but it’s not always the case.
'These can be high in calories, saturated fats and salt, so I would advise people always read the nutrition panel on the pack.
'My advice whatever type of diet you follow my advice, would be to cook as much as you can from scratch rather than relying on ready prepared foods because when you make something yourself you know exactly what has gone into it and you have complete control over the ingredients.'
Source: The Daily Mail