The healthiest supermarket cakes (and the ones to avoid)

While most cakes contain a fair amount of sugar, watch out for high sugar content, as this can lead to tooth decay and weight gain if too much is consumed over time.

A way to avoid these ingredients is simply to bake your own cake at home. “You don’t create ultra-processed foods (UPFs) at home, so it’s always going to be best to make your own cake,” Ludlam-Raine says.

“You can then swap ingredients to make the cake healthier, like using wholemeal flour, freshly grated carrot (if it’s a carrot cake), nuts and less sugar,” she adds.

How much cake you should eat – and when

“While enjoying cake occasionally is perfectly fine, moderation is key to maintaining a balanced diet,” says Ludlam-Raine.

The NHS recommends that adults consume no more than 30g of free sugars per day, which are those added to foods, rather than those found naturally in milk, fruit and vegetables. 

“Given that a typical slice of supermarket cake can contain 20-40g of sugar, it’s advisable to limit cake consumption to special occasions or once a week,” she says.

A correct portion size for cake would be around 70-100g, or the suggested serving size on the packaging. “But really, a larger slice of cake, or even having two small slices, on an infrequent basis, isn’t going to influence overall health,” Ludlam-Raine adds.

“You might get a blood sugar spike, followed by a ‘sugar crash’ from eating too much cake,” she explains. “Some people may also feel more lethargic after eating a high-fat and high-carbohydrate food like cake, because the body is working hard to digest it.”

When it comes to timing, it’s best to have it shortly after a meal as dessert, as the protein and fibre from your lunch or dinner slows down the digestion of the cake and the resultant blood sugar spike, Ludlam-Raine explains. Alternatively, you could go for a walk after eating cake, to limit the impact on glucose levels, she adds.

Ultimately, “if you really want a piece of cake, have it,” she says, “but put it on a plate, sit down, turn off the TV and enjoy it.”

“All foods can fit within our diet and all foods have a purpose, but it’s the portion size and the frequency in which you eat any type of food that determines how healthy you are.”

Nichola Ludlam-Raine (nicsnutrition.com, @nicsnutrition) is a specialist registered dietitian and author of How Not to Eat Ultra-Processed, which is published on July 18.