When you walk into a supermarket, you may just be thinking it's an innocent activity - that you're grabbing the food you need for the next few days. But to those behind the supermarket layout, it's much more than that: it's a maze designed to encourage you to buy more products, and often more expensive and less healthy products. I mean, who hasn't left the grocery store with a few more items than they expected - from the freshly baked bread that you just couldn't pass up to protein bars for those busy workdays. And you're not alone: as environmental psychologist and author of "What Women Want: The Science of Female Shopping" Paco Underhill noted to Bon Appetit, "Upward of 50 percent of what we buy in a supermarket we had no intention of buying as we walked in the door."

Let's look at three of the biggest tricks supermarkets use to get you to buy more products (and not necessarily healthier ones):

1. Store Layout

From the moment you walk in the door of the grocery store to the moment you pay and exit, your entire route has essentially been mapped out for you. For instance, think about the staples of a typical person's kitchen that will need to be replenished on a regular basis: eggs, butter, cheese, milk and yogurt. And where do are all of these items placed? In the back left-hand corner, ie. the furthest from the entrance that you could possible get. So, naturally, you'll end up passing enticing item after enticing item (on average, there are 47,000 different products in a supermarket) on your way to what you really wanted.

But supermarket designers don't just make sure that you pass a large selection of products - they micro-manage which products those are and on which side of you they sit. Studies have shown that humans like to move through a store counter-clockwise, which is why the aisles around the perimeter of the store, versus in front of the store, are often wider and more easily navigated with a shopping cart. In addition, the selection of products that are set up along the perimeter of the store is no accident: the store begins with flowers, produce, and baked goods, all products which will pique your senses - and trigger your salivary glands - and which are brightly lit to make it look more appetizing. Next, you hit the seafood and meats which are placed to the right of you - making it easy for people to grab, since most people push their cart with their left hand while grabbing items with their right. It's also not a coincidence that this section - following the fresh aroma of the produce and bakery - often contains the most expensive items.

2. Mixing Healthy With Unhealthy

While at one point the "perimeter" of the grocery store was known for being the healthiest, supermarkets are now using that mindset to add in unhealthy products with the healthy ones. For instance, when we see the that products are refrigerated, we make the assumption that they are fresher and thus, healthier. So when we see a product we already associate with some notion of healthiness - such as almond milk or Greek yogurt - we're even more likely to be pulled in by clever advertising. Look at Califia Farms Unsweetened Almond Milk for example: from the word "pure" sweeping across the container to the prominent display of "Only 40 calories per serving," this product screams healthy. However, as Mother Jones noted, Califia Farms is essentially charging its customers $3.99 for "a jug of filtered water clouded by a handful of ground almonds."

And how about the Greek yogurt that everyone raves about? While the plain varieties often only have 7 grams of sugar, some flavored Greek yogurts contain a whopping 19 grams of sugar - out of the 25 to 37.5 grams of sugar you're supposed to consume a day. Not surprisingly, these yogurts choose to highlight the fact that they're 'non-fat' instead of their sugar content, and can often reel people in who associate 'non-fat' with 'healthy.'

Yes, sugar is similar to cocaine in its addictive properties too. 

Another product which has been infiltrating supermarket perimeters is the protein and power bars. Often promoted as a healthy snack alternative, protein bars are often just candy bars in better wrapping. However, the placement of these bars around healthier foods can often trick people into believing that these bars are healthy too.

3. Misleading Marketing

When you look around supermarkets, it's no secret that more and more brands are trying to appear "natural" (another label that essentially means nothing): from the earth-tone packaging to the farm landscape printed on them, companies will do anything they can to associate themselves with the hip "slow, fresh, organic, local, etc., etc." movement. However, the phrases they use to lure people in can often be false. "Free-range" or "cage-free" eggs, for instance, gives the impression of chickens scampering adorably around a large, grassy knoll. However, even if chickens are "cage-free," they still often do not have access to the outdoors. And other companies can label their eggs "free-range," despite the fact that there are no government-regulated standards for free-range eggs, so these organizations may just let their chickens outside for a few minutes a day in a cramped area, and still tout a "free-range" egg product.

So what can we, as consumers, do to avoid this trap? On a personal level, we can stay informed and make sure to check the labels, instead of relying on false advertising. On a national level, we should demand more transparency in terms of food labeling. "We are what we eat" is not just a catchy phrase - it's a fact. And we must continue to support politicians who endorse healthy eating education programs, less deceptive packaging, and smarter FDA regulations.