Do you find your grocery bill sneaking up each time you shop? Once you’ve read these sneaky tricks supermarkets adopt to encourage us to buy more, you’ll never enter a store without a shopping list again.

Our bad memories are good for supermarkets. Most of us know the price of less than half a dozen food items, which puts stores in an advantageous position for manipulating prices. Some change prices several times a day.

Beware of supermarket jargon that aims to tap into your aspirations and cost you more. A prime example is the prolific use of the words ‘homegrown’, ‘local’ and ‘fresh’, which often are not a reliable indicator of quality.

Carts are getting bigger but that’s not necessarily because we want to buy more. Research shows a larger cart makes us inclined to unintentionally purchase more.

It's not only bigger carts that encourage us to buy extra; bigger bulk packs make us consume more than we need. So that 16-pack on special offer may be a false economy as you’re more likely to finish it sooner simply because it’s there.

There’s a reason value ranges look unenticing – it’s to repel customers who can, so will, pay more for products. The quality may be just as good as a more expensive item.

In the US, eggs can be sold for up to 30 days after they’ve been packaged (not laid, packaged) so it’s perfectly possible that shop-bought eggs are up to two months old. They wouldn’t be sold if they’re harmful to health, but the fresher the egg the easier it is to cook and the more nutritious it is.

Think you’re doing your body some good by drinking fruit juice? Not if it’s made from concentrate; not only could it be up to a year old, it will have been through so many processes to preserve it there’ll be little nutritional benefit.

Freshly made bread? Mmmm, not so sure. In the UK, the Real Bread Campaign found that some supermarkets sell fresh bread that’s actually ready-made or part-baked elsewhere then finished on-site.

Seafood is not necessarily the food you see. A major study by ocean conservation group Oceana found that around a third of seafood sold in grocery stores, markets and restaurants in the USA was not what it claimed to be. Instead it was a cheaper, overfished or even risky to consume species. The two most commonly mislabeled fish were snapper and tuna.

Shrink-wrapping a cucumber or packaging broccoli may preserve the vegetable’s life by up to a week, but it's adding unnecessary packaging and cost to your grocery shop. Not to mention the environmental impact.

According to the editor of supermarketguru.com, Phil Lempert, you should shop at quiet times as we buy more when it’s busy because humans naturally want to be part of a crowd. So, avoid weekend visits and aim to do your weekly shop earlier in the week.

Research conducted by Mood Music, using a virtual supermarket created by Wageningen University in the Netherlands, found that shoppers spent up to 15% more time in a store where gentle music was playing, while people shopped quicker when there was no music or loud songs.

According to Martin Lindstrom, supermarkets have started to make shelf space at checkouts smaller when it was discovered that more than 60% of shoppers ditch items before buying.

According to British consumer champions Which, the airy space at the front of a store works to help shoppers “adapt to the store’s environment and slow their pace to ‘shopping speed’.” The less rushed the customer, the more they’re likely to buy more.

Supermarkets deliberately display extravagant items as you walk in to put you in a good mood, and because you’re more likely to buy luxuries at the beginning of your shop before you’ve spent a small fortune on essentials.

It’s not unusual for supermarkets to put everyday staples like bread and milk at the back, so shoppers are lured into buying other products en route. Which? magazine claimed that “supermarkets want you to be enticed by other goods before you get to what you need".

Lanes are not expansive to help you turn your cart easily, says Which? magazine. It’s so you’re not distracted from looking around at products, which you would be if were trying to squeeze your way past other shoppers.

Supermarkets are businesses, they’re not in the game to be generous. Brands pay big money for top spots and will draw you in with special offers that often seduce you into paying for something you don’t usually buy.

Two-for-one items can save you money but check how much just one costs first – if the difference isn’t that much you could well be purchasing something you don’t really need because the offer seems so good.

A product with 25% or 50% off may seem like a bargain but it’s only that if it’s something you buy regularly. Work out the price per weight to help you decide if it really is the steal it seems to be.

The free samples that supermarkets hand out are inclined to make you feel both guilty and treated. As a result, shoppers are more likely to buy the product – whether they need it or not – out of a sense of duty or because they feel they can afford to, having got something for nothing.

This is a particularly dirty trick – supermarkets will use different measurements per unit to confuse shoppers. For example, they might mark one product up as X amount per liter, but a similar product as X amount per 100ml, leaving you to do the sums. It stops us from comparing prices and encourages us to buy the product that displays the smallest amount even if, when added up, that product costs more.

It pays for promotional signs and branding to be vivid – red is a popular color. This is because it’s more visible to the human eye (in nature red often signifies danger) so we’re more likely to spot it, and it stimulates appetite.

When it comes to branding, upmarket products will opt for traditionally imperial hues, such as dark red, gold or purple, while health products sell well in tones we associate with nature and freshness, such as green and white. Yellow is a happy, upbeat color, and blue suppresses the appetite but inspires feelings of trustworthiness.

For years, brands paid more money to have their products placed at eye level, around 5 foot (1.6 meters) from the floor, but Simeon Scamell-Katz, analyst and author of The Art of Shopping, found this to be a fallacy. Using eye-tracking devices he determined that shoppers look further down, at hand level, and it’s those shelves that make the big bucks.

Big brands such as Coca-Cola and Nescafe play a key role in guiding shoppers to food categories. Known as ‘signpost brands’, they are key to helping shoppers realize that they’ve reached the aisle they’re looking for.

Supermarkets make easy money from harassed parents by placing enticing products within children’s reach – knowing that they may concede in order to avoid a tantrum.

Supermarkets like to pair up products that we associate together. For example, if you need coffee or tea your memory (or your stomach) will also be attracted to the cookies strategically placed close by – even if you had no intention of buying treats.

This is another particularly cheeky trick: you’re in a hurry when you spot neat, pre-cut packaged produce that’s easier to grab than finding a bag and weighing it out yourself. But loose, whole fruit and vegetables are not only significantly cheaper, they avoid unnecessary and wasteful packaging.

Think the supermarkets are doing you a service by offering you 48 different granolas? This ploy is to make you feel like the options offered are satisfying your every whim. However, research shows that people are generally overcome by too much choice and find it harder to make decisions, which is why brands will pay extra to have standout products on display at the end of an aisle.

Never go shopping on an empty stomach. Why? Because supermarkets deliberately put snacks and sweet treats by the checkout knowing that if you’re tired or hungry you’ll buy them. The same goes for the magazine you’ve half-read while waiting in line.

Your loyalty card is only loyal to the store. Loyalty card schemes gather essential data about your buying habits, which is then effectively used to tempt you to buy more, more, more.