Many foods that we don't expect to be sweet contain a surprisingly large amount of sugar. Some ready-made stir-in sauces can also be higher in sugar than you expect. One third of an average-sized jar of pasta sauce (roughly 150g) can contain more than 13g of sugar, including added sugar

When eating out or buying takeaways, be careful of dishes that are typically high in sugar, such as sweet and sour dishes, sweet chilli dishes and some curry sauces, as well as salads with dressings like salad cream, which can also be high in sugar. Sauces such as tomato and chilli can have as much as 23g of sugar in 100g which is roughly half a teaspoon per serving.