The rules for healthy eating aren't a closely guarded secret. We've been told repeatedly that eating more whole foods and fewer convenience foods is the way to better health. So if we know it, why don't we just do it?
Because the road to better eating can be littered with obstacles. Habits hardwired from childhood, genes that can affect taste preferences, even the people you share food with, are just some of the influences that can affect food choices. And let's not forget the marketing messages aimed at persuading us to eat food that can make us sicker not healthier.
"For every dollar the World Health Organisation spends on initiatives to better the nutrition of the world's population, the food industry spends $500 promoting processed food."
"People know that an apple is healthier than a lamington – it's sticking with the apple that's difficult," says nutritionist Leanne Cooper. "The gap in our nutrition education isn't lack of knowledge about which foods are healthy but about how to change our behaviour."
Cooper, the author of a new book Change the way you eat: the psychology of food, believes that making healthier choices has become harder and that food marketing can take some of the blame.
"For every dollar the World Health Organisation spends on initiatives to better the nutrition of the world's population, the food industry spends $500 promoting processed food," she says.
Her approach to better eating habits doesn't focus on weight loss. Instead she's created a primer on the factors that encourage us to overeat or eat the wrong thing – including the influence of food marketing – and how understanding them better can help reshape our eating.
Cooper doesn't pretend this is easy. Although life events like pregnancy and health scares can sometimes turn us into vegie lovers overnight, reshaping behaviour usually takes time. Her advice: hasten slowly rather than attempt too much too soon, which can set you up for failure – and guilt.
"Choose just one thing to work on first – for example, snacking at night or eating while cooking – and wait until the new habit is well entrenched before you move on to the next target," she says. "Select the top eating habit you think gets in the way of healthy eating and start from there."
She also urges avoiding negative experiences around eating and to focus on efforts to make healthier food choices rather than on restraining eating which can act as a punishment. It's better to be guided by your hunger signals and focus on food and health not food and guilt.
Some strategies work on changing the eating environment. Some examples: planning meals the night before to avoid making rash decisions; making healthy food easily accessible at home; downsizing your plate (a tactic that can have a real impact on portion control, says Cooper); separating leftovers into small containers to avoid eating everything at once; when you eat with others, start eating last so you're more likely to eat less.
"The people you eat with also influence your food intake – if others finish before us we tend to stop eating," Cooper says.
But other tactics work on getting a better grasp of how you interact with food – what are the eating habits you want to change, for instance? What are the factors that spark them off – stress, an argument, being in a particular place or watching a particular TV show are some common cues – and what can you change to avoid habitual triggers?
As for tackling overeating, Cooper advises a golden rule: wait 20 minutes after finishing a meal before you decide you're still hungry. It takes an average of 20 minutes from the end of a meal before you feel full, she says – the time it takes for your stomach to empty its contents into the intestinal canal and for signals of satiety to kick in. She also explains the factors that can leave you feeling hungry after eating – including a meal with too little protein (of all nutrients, protein stimulates satiety the best) or one that includes more intensely flavoured sweet and savoury foods that can make it easy to keep eating.
Speaking of flavours, if your taste buds are attuned to the saltier, sweeter flavours of convenience food, you might dismiss natural flavours of fresh foods like vegetables as being too bland, but tastebuds can be retrained.
"There will always be some flavours you'll be resistant to – if you were forced to eat something as a child, for instance, or if a particular food made you feel sick. But by and large if you keep eating something you'll learn to like it. Pairing an unfamiliar food with a food that you already like can make this easier – like adding a little grated cheese to vegetables or stirring lentils into casseroles as a thickener."
Change the way you eat. The psychology of food by Leanne Cooper is published by Exisle, RRP $29.99. Also available as an eBook.