That mozzarella panini you had at lunch time could be causing you to miss out on your dream family holiday.
It may sound silly, and you may be wondering "how?" but research suggests Britons are forking out thousands of pounds a year on shop-made lunches - money they could easily save.
Supermarket giant Asda has urged customers to "use their loaf" as it was revealed that half of Britons buy their lunch two or three times a week, and one in five buy lunch five days of the week.
The dramatic price findings come as living costs rise at double the rate of wages, and as many families struggle with their finances.
Those who make their own sandwiches at home could be £1682.20 better off each year (this research is based on lunch of tuna sandwich, yoghurt, apple and bottle of water) compared to someone who buys lunch components from a shop chain.
This money could be used for a summer holiday for a family of four, or to pay for your household's yearly electricity bill, which is £1,127 on average.
If you buy your lunch every day, find out how much you can save with this savvy spending calculator.
Some sandwich chains which Britons may think are great value for money can be much more expensive than a home-made sandwich, the research found.
The cost of a tuna mayonnaise sandwich at Greggs (£1.45) is 120% higher than if you made one at home using products from Asda (66p).
On average, customers pay 349% more to buy lunch at sandwich chains, compared with supermarket prices, their research found.
An Asda spokesperson says: "We think it's shocking how much the costs of a daily trip to the sandwich shop at lunchtime can soon mount up.
"With a little bit of forward planning to prepare your lunch the night before, or simply popping a pre-bought lunch pot into your work bag, Brits could save thousands of pounds each year - we're urging our customers to use their loaf!"