Getting people to change their behaviour is difficult – just ask any scientist who works in climate change. Similar challenges apply to any dietician. This week, an international group of researchers published a paper proposing a radical new diet, as part of a symposium on health and food run by The Lancet.
In the report, they say that this diet could feed the world’s growing population (estimates put the global population at ten billion by 2050), as well as potentially change agricultural practices and stop the earth from sliding into further environmental devastation. One of the major challenges which this diet would hope to tackle is the role of livestock farming in contributing to climate change.
In November, the world’s science academies issued a report stating that the global food system is fundamentally broken, and that improving it would require big changes to how we produce, consume and transport food. However, even though the diet itself proposes large changes, the reasoning behind it is similar to what scientists have been saying for years.
It requires cutting down on unhealthy foods, such as red meat, and increasing the intake of grains and vegetables. A detailed breakdown can be found in the Lancet report itself. Roughly, you should be aiming to eat 2,500 kcal per day, which is around the general guidance of how much an adult should eat now. The crux of the diet would involve a far greater reliance on beans, legumes and lentils for protein – this would form about 75g of your daily food intake. You should be cutting down meat consumption to at most 14 grams of red meat and 29g of chicken per day, and aiming to have around 500g of fruit and vegetables.
For some, those diets aren’t necessarily unusual– for example, vegans already don’t eat dairy and rely heavily on vegetables and other kinds of complex carbs for the majority of their food supply. But in order to encourage widespread adoption of these dietary changes, there would have to be an incentive: previous research has demonstrated that changing health-related behaviour is notoriously difficult. For example, in North America, meat is considered a daily staple, and in parts of Europe, dairy is embedded in local cuisine, from cheese to milk and yoghurt (under this diet, a glass of milk would be the recommended daily intake).
“People are slightly influenced by conscious decision making, such as putting a sustainable label on an item of food, but we actually now know that it doesn’t tend to work,” says Brian Power, who researches nutrition and behavioural change at UCL. “The other, more effective approach is trying to affect unconscious decision making, so increasing cues in the environment, and making the change more socially acceptable.”
One successful example is most likely the five-a-day campaign, which was introduced 15 years ago. This campaign was introduced by the government to change people’s diets, particularly for young people. But simply knowing that something is better for us is often not enough to increase the acceptability of certain practices – e.g. cutting out meat – or doesn’t give us the right incentives to make a change. In reality, the information about how bad our agricultural practices are for the planet, for example, or the impact of climate change on our local environment – a lot of this information is widely publicised and easy to find.
For a long time, public health campaigns and government intervention has tried to use changes in packaging – such as adding emissions or miles travelled by an item – in order to make individual consumers consider what they’re buying more carefully. But the evidence that this has actually worked is limited. “Actually, the interventions which tend to be the most popular also tend to be the least effective,” says Power. “We’ve found that public health campaigns are really bad at communicating the risks to people.”
This is often for two reasons – one is that it’s hard to say with complete certainty how the consumption of meat, or dairy, or eggs, or even beans and lentils, affect our planet because the figures vary according to different estimates. The other reason is one of motivation – even though we know that climate change is bad and that we should all be doing more to make it stop in its tracks – a change towards making our life greener is far more difficult. Even if you do make the change to a different kind of milk, or start biking to work, it can be hard to maintain habits over a longer period of time, especially if they either require more effort or are more expensive.
Effort and expenses are often identified as the main reasons that people don’t switch to healthier diets – either because it’s too difficult to, or it’s just not worth the money in their eyes. So what needs to actually be done to get people to take it seriously?
“You have to emphasise the positive consequences of the change,” says Tali Sharot, a professor of experimental psychology at UCL. “Rather than saying, you’ll be unhealthy and it’ll be bad for the environment if you eat these specific kinds of foods, you have to say, okay, for you as a person, you will live longer, have more energy, look better – if you do these things.”
Also, the social elements of what’s acceptable and what isn’t can provide the impetus for people to change their lifestyles in ways that they might not otherwise. The increase in vegan and vegetarian diets around the world have had a knock-on effect, especially if celebrities or people that are widely respected are shown to be adopting those diets. “You can create social incentives at different levels,” says Sharot. “It’s easier if governments step in, but social acceptability can play a big role in it.”
However, a major hurdle is that the problem is global. Individual governments, or even large corporations, won’t be able to cause widespread dietary change in the way that scientists are encouraging. “Changing the food supply chain will have the most significant transformational effect,” says Power. “This is not going to work with health and science professionals working in a silo. We need to reduce people’s demand for a product.”
One way to do this would be to impose taxes on foodstuffs which are widely known to be unhealthy. Although suggestions to tax meat have been unpopular with the public, and with politicians, there is widespread evidence to suggest that it works – in terms of changing agricultural farming practices to make them more sustainable, as well as reducing meat consumption.Known as a sin tax, this would be similar to the tax that has been placed on sugary drinks. In the last few years, as the impact of the livestock industry on the global climate has become increasingly publicised, researchers have started to suggest that a meat tax is inevitable.
Christopher Gardner, a nutrition researcher at Stanford University, says that linking the various aspects of sustainable practices to different parts of people’s lives could also cause a behavioural change. This means using discussions around better labour practices or animal rights to motivate individuals to make better choices around nutrition – even if climate change isn’t at the top of their agenda, other issues might be. In the long term, that could provide the drive for people to stick with the dietary choices they’ve made.
Yet, scientific literature has established that people often eat in unhealthy ways because it can be difficult to access healthy food – and to do it without a significant amount of expense.
“We’ve found time and time again that availability and accessibility within the environment is what helps people change immediately,” says Power. This would require making environmentally friendly food accessible to low income communities, and implementing nutrition plans in schools that can be made fresh and cheaply.” But this requires a convergence of other factors – such as market dynamics, supermarkets taking corporate social responsibility seriously. All of that will have to come from the government, and from policy makers.