28/05/2014 13:29 BST | Updated 28/07/2014 06:59 BST

Sweet Relief in Supermarkets

Last week, I found myself in a supermarket that I didn't usually shop in. Armed with a trolley and a list from my wife, I was ready to get the job done - in and out in 20 minutes. But my surroundings were different and the supermarket's layout didn't reflect the one at my normal store's. Before I knew it, my list may as well not have existed. I was buying haphazardly and drawn to brands I'd never even heard of.

As I approached the checkout, I didn't feel like I'd glided smoothly through this job but rather zigzagged my way back and forth, and up and down. So, almost subconsciously, I grabbed a chocolate bar displayed by the checkouts for a bit of a reward.

But I didn't need that chocolate bar, nor would I have bought it if it hadn't been under my nose. How many other people do this every day, I wondered?

As if my thoughts had predicted the headlines, the next day I read that Tesco is to ban sweets and chocolates from all its checkouts. The supermarket giant found that 65% of shoppers backed confectionery being removed from checkouts to help them make healthier choices when out shopping. And 67% of people said it would help them choose healthier options for their children.

Now, this isn't the first time that this topic has been raised - or even addressed. 20 years ago, over 700 of Tesco's larger stores removed sweets and chocolate from their checkouts. It now vows to remove tempting, unhealthy treats from checkout tills at all stores, including its Metro and Express branches. They plan to test a variety of healthier products in their place.

This initiative follows a previous commitment from Tesco to make soft drinks, sandwiches and ready meals healthier by lowering their sugar, salt and fat content.

But how much influence can supermarkets have when it comes to helping people make healthier choices? Sweets, chocolate and other unhealthy foods are still available to purchase. Can the layout of a store or the offering of healthly alternative really create a behaviour change at a population level?

A study led by the Chairman of the National Obesity Forum, carried out last year, set out to explore just that - what potential does the supermarket environment have to encourage healthier choices?

The study found that shoppers are more likely to buy healthier foods in the supermarket if they are faced with strong visual prompts. Prompts included life-sized figures of health professionals, such as doctors, bearing the message 'Let's Shop Healthier' near healthy foods, such as fruit and vegetables. The same message was also displayed both inside and outside the store, such as at the entrance, on floor stickers and at points of sale. And free reusable fruit and vegetable bags were provided in the fresh produce section.

The study saw the sale of fresh and frozen fruit rise by 20% and 30%, respectively, over a 15 week period. Interestingly, most of the visual materials were displayed in the fruit and veg section at the front of the store. This area, according to the study, is considered to be the 'priming zone', meaning that shoppers are primed or predisposed to shop healthier throughout the store from the start.

Studies like this, I believe, give a great insight into shopping behaviour and could help shape health promotion policies and healthier living campaigns. We're bombarded by offers on unhealthy products in supermarkets constantly. 'Buy one get one free' offers on fizzy drinks, crisps and biscuits are commonplace in all stores. Surely this signposting could easily be shifted to healthier choices?

Looking into how our environment can affect behaviour change, I came across an editorial in the British Medical Journal which gave a great overview and potential insight into how supermarkets could play a part. Written by the director of the Behaviour and Health Research Unit at the University of Cambridge, it said: "The removal of cues for unhealthier behaviours and the addition of ones for healthier behaviours has the potential to shape the behaviour of all those exposed, regardless of their executive functioning. Although plausible, this potential is untested."

The article explains how our capacity to resist environments that tempt us to overeat, smoke or be physically inactive is influenced by the strength of our 'executive functioning' - this is how our mind regulates behaviour and thought.

Further supporting this theory, a study published very recently in the American Journal of Clinical Nutrition showed that marketing strategies can increase the sales of healthier foods and beverages. Stores that used promotion strategies showed higher sales of low-fat milk and water, and healthier frozen meals.

It seems that supermarkets have a big role to play when it comes to helping people make better choices. Simple strategies, such as removing chocolate and sweets from checkouts and prompting the sale of fruit and veg, is a start. But can we apply similar ideas throughout the whole store? It's also a question of getting all supermarkets on board. The confectionary market is a profitable one, as are many other unhealthy products. Behaviour change on a large enough scale can't happen without a supportive environment. Supermarkets may be making headway, but a joint effort from all sectors of the food industry and government are needed to make a significant change.