A BMI score of 25 or more is classed as overweight, while 30 or more is obese.

London - From using tempting smells, meal deals and super-sized portions, there are numerous ways the fast food industry is indeed fuelling the obesity epidemic by encouraging us to eat more, according to Buzzfeed.

Here we delve further into some of these tricks of the trade...



A scientific study carried out by Brian Wansink at the University of Illinois investigated the ways people over-consume based on the way food is presented to them.

When it comes to why people decide to eat at fast food restaurants, Wansink refers to a study that found, “aside from hunger, participants claimed they started eating because of the salience of food (‘I saw the food’), the social aspects of eating (‘I wanted to be with other people’), or simply because eating provided them with something to do”.

Fast food chains all play on these desires in the way they are positioned and marketed. By having restaurants in shopping centres and motorway service stations, they can tempt people in to eat when they’re shopping or driving somewhere – even when they’re not hungry.

They entice people by showing pictures of the food on offer in window display posters and on large, bright boards above the tills.

They play on the “wanting to be with other people” aspect by providing a space for people to sit down around a table and eat together, rather than having long benches of seats where people can’t interact with one another or having no seating area at all.

Providing a space for people to sit and eat also means they are more likely to stay longer and eat more courses – returning for dessert or another fizzy drink.



The scent of the restaurant can influence how much people eat too as “odour can influence food consumption through taste enhancement”.

Thus by piping pleasant scents into their restaurants, fast food chains can encourage people to eat more. They can also do this by making people queue and order at the counter, rather than offering table service. This means the customer has to wait to see the person in front of them being served their food at the counter on a tray. The first customer will then walk back past the waiting customers who will see and smell the food on their tray – again enticing the waiting customer to order more when it’s their turn.

The music fast food restaurants play can also effect how much we eat. Hearing soft music that’s not too up-tempo has been proven to encourage diners to stay at a restaurant longer and eat more. Hence, slow songs and easy going pop music is played in fast food restaurants – not drum and bass or techno dance tracks.



Fast food chains have made it easier than ever for people to eat there – from offering drive-throughs so you don’t even have to leave the comfort of your own car to be served, to meals deals where you can get a drink, main meal and dessert all in one go.

This isn’t to make life easier for the time-strapped customer but again to make them consume more. Studies have found that one of the strongest influences on consumption is ease of access.

This refers to the effort it takes to obtain the food and the ease required to eat it. Fast food restaurants solve this by serving food quickly and in a way that’s easy to eat. It’s wrapped in paper or a box that’s easy to open and you don’t need to worry about a knife and fork or cutting up the food first – as you can eat the burgers, chips and nuggets with your fingers.



Meal deals are a further way to get people to eat more. They encourage people to think they are saving money when they could actually be buying more food than they need. Studies have shown that by offering people variety they are more likely to overindulge.

So a meal deal where a person gets chips with their burger means they’ll eat both – even if they were only actually hungry enough to eat one or the other.

The way the portions are served also encourages over-eating. Having one bucket of chicken means people are more likely to eat all the chicken in the bucket as it’s perceived as one portion.

But if the same number of pieces of chicken were divided into three boxes, people are less likely to eat the contents of all three.

Wansink points out that “although the physical effort to open the small component packages is minimal, a psychological barrier may prevent individuals from opening another item if they have already opened and eaten several of them”.

He added: “Follow-up lab studies suggest that people tend to eat less when offered multiple small packages than when offered a large package of the same volume. Part of the reason is that the smaller packages provide discrete stopping points for a person to reconsider whether he or she wants to continue eating.”

Fast food chains eliminate these “stopping points” by serving their foods in one large portion whether that’s a big fizzy drink served in a large, wide container rather than a tall, thin one, a bucket of chicken rather than a small box or a burger containing three slices of beef instead of just one.



Fast food chains offer their products in a variety of sizes and the largest is often presented as good value. Those buying large sizes are more likely to consume the whole thing, as explained above, but are also not always likely to be alarmed by the amount they have consumed.

This is another crafty trick of the fast food industry – they have made consuming large portions seem to be “the norm”.

Wansink explains: “The more general explanation of why large packages and portions increase consumption may be that they suggest larger consumption norms. They implicitly suggest what might be construed as a ‘normal’ or ‘appropriate’ amount to consume. Even if individuals do not clean their plates or finish the package, the larger size gives them liberty to consume beyond the point where they might have stopped with a smaller, but still unconstrained, supply.”

He added: “People can be very impressionable when it comes to how much they will eat. There is a flexible range as to how much food an individual can eat and one can often ‘make room for more’.

“For many individuals, determining how much to eat or drink is a relatively low-involvement behaviour that is a nuisance to monitor continually and accurately, so they instead rely on consumption norms to help them determine how much they should consume.

“Food-related estimation and consumption can be influenced by other norms or cues that are present in the environment. Many seemingly isolated influences of consumption – such as package size, variety, plate size, or the presence of others – may involve or suggest a consumption norm that influences how much individuals will eat or drink.” – Daily Mail


Tricks used

* Pictures of food tempt people to want them even if not hungry

* Appealing smells piped into restaurants increase appetite

* Large portions marketed as the norm so people don’t feel alarmed about eating whole thing

* Serving food in one big receptacle rather than smaller containers encourages over-eating

* Meal deals encourage people to eat sides and desserts they don’t need