We know what to eat to stay healthy. So why is it so hard to make the right choices?

A healthy diet protects us against a number of chronic diseases, including heart disease, diabetes and cancer.

From early childhood, we receive an abundance of information about how we should eat to be healthy and reduce our risk of disease. And most people have a broad understanding of what healthy eating looks like.

But this knowledge doesn’t always result in healthier eating.

In our new research, we set out to learn more about why people eat the way they do – and what prevents them from eating better. Lack of time was a major barrier to cooking and eating healthier foods.

How do you decide what to eat?

We spoke with 17 adults in a regional centre of Victoria. We chose a regional location because less research has been done with people living outside of metropolitan areas and because rates of obesity and other diet-related health issues are higher in such areas in Australia.

Participants included a mix of people, including some who said they were over their “most healthy weight” and some who had previously dieted to lose weight. But all participants were either:

• young women aged 18–24 with no children
• women aged 35–45 with primary school aged children
• men aged 35–50 living with a partner and with pre- or primary-school aged children.

We selected these groups to target ages and life-stages in which shifts in eating behaviours may occur. Previous research has found younger women tend to be particularly concerned about appearance rather than healthy eating, while women with children often shift their focus to providing for their family. Men tend to be less interested in what they eat.

We asked participants about how they decided what food to eat, when, and how much, and what prevented them from making healthier choices.

It’s not just about taste and healthiness

We found that, although such decisions were determined in part by taste preferences and health considerations, they were heavily influenced by a host of other factors, many of which are outside the person’s control. These included other household members’ food preferences, family activities, workplace and time constraints, convenience and price.

Healthy eating means consuming a balanced diet rich in nutrients, including a variety of fruits, vegetables, whole grains, lean proteins and healthy fats, while limiting processed foods, added sugars and excessive salt. Healthy eating also includes how we eat and how we think about food and eating, such as having a positive relationship with food.

One 35- to 45-year-old woman, for example, said that time constraints and family preferences made it difficult to prepare healthier food:

I love the chance when I can actually get a recipe and get all of the ingredients and make it properly, but that doesn’t happen very often. It’s usually what’s there and what’s quick. And what everyone will eat.

One of the 35- to 50-year-old men also noted the extent to which family activities and children’s food preferences dictated meal choices:

Well, we have our set days where, like Wednesday nights, we have to have mackie cheese and nuggets, because that’s what the boys want after their swimming lesson.

Research shows that children are often more receptive to new foods than their parents think. However, introducing new dishes takes additional time and planning.

An 18- to 24-year-old woman discussed the role of time constraints, her partner’s activities, and price in influencing what and when she eats:

My partner plays pool on a Monday and Wednesday night, so we always have tea a lot earlier then and cook the simple things that don’t take as long, so he can have dinner before he goes rather than buying pub meals which cost more money.

Despite popular perceptions, healthy diets are not more expensive than unhealthy diets. A study comparing current (unhealthy) diets with what the Australian Dietary Guidelines recommend people should eat found that the healthy diet was 12–15% cheaper than unhealthy diets for a family of two adults and two children.

However, learning and planning to prepare new types of meals takes effort and time.

Simply educating people about what they should eat won’t necessarily result in healthier eating. People want to eat healthier, or at least know they should eat healthier, but other things get in the way.

A key to improving people’s eating behaviours is to make it easy to eat more healthily.

Policy changes to make healthy eating easier could include subsidising healthier foods such as fresh produce, providing incentives for retailers to offer healthy options, and ensuring access to nutritious meals in schools and workplaces.

So how can you make healthier food choices easier?

Here are five tips for making healthy choices easier in your household:

1. If certain days of the week are particularly busy, with little time to prepare fresh food, plan to cook in bulk on days when you have more time. Store the extra food in the fridge or freezer for quick preparation.

2. If you’re often pressed for time during the day and just grab whatever food is handy, have healthy snacks readily available and accessible. This could mean a fruit bowl in the middle of the kitchen counter, or wholegrain crackers and unsalted nuts within easy reach.

3. Discuss food preferences with your family and come up with some healthy meals everyone likes. For younger children, try serving only a small amount of the new food, and serve new foods alongside foods they already like eating and are familiar with.

4. If you rely a lot on take-away meals or meal delivery services, try making a list ahead of time of restaurants and meals you like that are also healthier. You might consider choosing lean meat, chicken, or fish that has been grilled, baked or poached (rather than fried), and looking for meals with plenty of vegetables or salad.

5. Remember, fruit and vegetables taste better and are often cheaper when they are in season. Frozen or canned vegetables are a healthy and quick alternative.

Read more: Cost of living: if you can't afford as much fresh produce, are canned veggies or frozen fruit just as good?