Healthy eating is more likely to become a habit when most of those around us are engaging in the same behaviours.

Most of us know what sort of food we should eat to optimise our health and help avoid lifestyle diseases like obesity and heart disease. But we don't stick to our ideal diets.

Part of the reason is that food producers and retailers spend a lot of money trying to influence our food choice toward more expensive and processed food, the sort we're overeating. But several things can be done to encourage healthier eating.

We recently reviewed research investigating how to promote healthy eating when dining out. The review found manipulating the environment in dining and shopping areas, as well as some behavioural techniques, can make healthy choices more likely.



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123RF Making people aware of the time it takes to burn off a slice of pizza could encourage them to make healthier choices.

DOING WHAT'S CONSIDERED NORMAL

Humans get a large amount of information from watching the people around them, and it's important to us to fit in.

123RF Healthy "food architecture" in supermarkets can help us to select healthier foods.

We do this and understand how to act by watching the language, posture and activities of others. These are social models or norms, and we get information about what is a normal diet by seeing what other people eat.

This is so strong that when we see people eating healthy foods in small portion sizes, we're more likely to choose lower calorie foods in smaller serves. This means we can influence our families, including our children (and possibly even teenagers) and our colleagues, to eat better while reaping the benefits of eating better ourselves.

Organisations like hospitals, staff canteens and schools can also harness the power of social norms by displaying healthy meals of an appropriate size as normal and pleasurable choices made by people like us.

TANGIBLE LABELLING

Fortunately, the responsibility of food producers to provide measurements of the energy contained in foods they produce is well established.

Unfortunately, there is evidence kilojoule counts don't influence people to make lower kilojoule choices when they appear on menus. It seems the kilojoule and calorie count numbers are too abstract to influence most people.

What does seem to work is translating those numbers into a meaningful rating system. Kilojoule counts are more effective if we relate it to something tangible, such as the number of minutes of a specific exercise someone would need to do to work off the energy in a meal.

For example, making people aware it takes two hours of walking to burn off a can of cola could encourage them to make healthier choices.

Any organisation providing food can use this method, which could apply to meals, snacks and drinks sold for eating in, taking away, or even in vending machines. There are some easy to use sources of kilojoule-activity ratios, including one from the Cancer Council NSW.

PLATE SIZE

Although there is good evidence social norms and tangible labelling influence healthy eating behaviours while dining out, not every method to encourage healthy choices is effective.

Studies have proposed choosing a smaller plate or fork encourages people to eat less. It seems logical that a meal would seem larger if it's on a smaller plate.

But when tested experimentally, this technique doesn't work consistently. When it does work, it may work only on those who already have a healthy weight.

On the bright side, this is a timely reminder of why efforts to change behaviour should be based on evidence and also tested in the field. When something sounds like it works, and has a logical pathway of influence so we understand how it would work, it still might not work in the field.

STRATEGIC POSITIONING

There has long been the assumption that increasing the availability or manipulating the placement of healthy food within places like supermarkets and cafeterias will lead to consumers making better choices. This technique is called "food architecture" and its logic makes sense, as marketers have been using principles of product placement to encourage us to buy certain products and spend more money for a long time. But can we assume the same principles for healthy food placement?

While there is some evidence to suggest that manipulating how food is positioned in a store can increase the sales of healthier options, the fact that we are still constantly bombarded with alternative products and considerations such as cost make it unlikely that placement alone will sway our choices.

A recent review of studies into food architecture concluded that while healthy food placement does show promise for increasing healthy food choice, we still need to learn more about how it actually influences diet and obesity levels.

MANIPULATING PEOPLE

Even if these techniques are effective, is it ethical to influence peoples' eating behaviour without their knowledge? Researchers and policymakers do think about the ethics of influencing people.

In our daily lives, we're subjected to many efforts to influence us one way or another, from government policy to marketing and advertising. Even the weather influences our decisions.

Work to change people's behaviour, also called "nudge" and "choice architecture" by researchers and governments, only changes elements of the space around us that may encourage us to make particular choices. It doesn't take any decision out of our control.

And the opportunity to support people to be more healthy without costing them more, punishing them, or taking away any of their choices, is too good to pass up.

Breanna Wright is a research fellow at Monash University. Denise Goodwin is a research Fellow at Monash University.

- theconversation.com