Healthy diets are often accused of being too costly for people on a low income. But a large Brazilian study has suggested the increased cost can be curbed when a healthy diet becomes more environmentally friendly.
What’s more, the pressure on the purse strings of moving towards a healthy sustainable diet can be eased by focusing on local food habits and supplies, say the authors.
Concerns over the cost of the EAT Lancet recommendations
The Eat-Lancet reference diet represents a healthy and sustainable global diet that can help to reduce diet-related greenhouse gas emission (GHGE). However, experts are concerned that many people around the world couldn’t afford to follow this type of diet.
And for the reference diet approach to have a real impact, it is important to consider food costs, particularly for low-income populations, say the authors.
Quest for a healthy sustainable diet in Brazil
Brazilian people are among the world’s biggest consumers of meat, whereas they eat relatively few fruits and vegetables. This is at odds with experts’ consensus view that the most effective way to lower diet-related GHGE is by eating only a little meat and plenty of plant foods.
This diet-modelling study looked at the dietary changes needed both to improve nutrition and to reduce diet-related GHGE across populations and various income levels in Brazil. Food consumption and prices were obtained from two large nationwide surveys of nearly 56,000 households and over 34,000 individuals. The authors then designed several diets that met a variety of nutritional, cultural and environmental requirements, while staying as close as possible to people’s usual diets.
Household income and diet cost
Results showed that across the population of Brazil, changing the diet so that it followed dietary guidelines reduced GHGE by up to 27% but increased diet cost by up to 24%. This healthy diet involved eating more beans, fruit, vegetables, dairy, fish and chicken, and less red meat, rice, high-fat/sugar/salt foods and oils.
Adopting a healthier diet meant a bigger spend on food for people on a low income. Being aware of local food habits and introducing feasible food shifts may help to ease costs, say the authors.
Reducing GHGE further (by 30–60%) did not necessarily increase the cost of a healthy diet, and in fact tended to reduce cost. This was due to a progressive reduction in meat and high-fat/sugar/salt foods, which are expensive.
How low is too low when it comes to GHGE?
Increasing diet quality and reducing GHGE by more than 30% required dramatic changes from the usual diet which people may find more difficult to adopt. It is possible to reduce GHGE by up to 70%, but with the further reductions in animal-based foods such as dairy there is a danger that the diet wouldn’t provide enough calcium, the authors warn.
‘…although the Eat-Lancet reference diet was considered unaffordable for most of the low-income populations worldwide (Hirvonen et al., 2020), our results suggest that its predicted cost may be lowered, by taking into account local food habits (i.e. feasible food shifts in the local context).’ – Verly-Jr, 2021.
Definion of the sustainable healthy diet
The Food and Agriculture Organization (FAO) of the United Nations definition is: ‘Sustainable diets are those diets with low environmental impacts which contribute to food and nutrition security and to healthy life for present and future generations. Sustainable diets are protective and respectful of biodiversity and ecosystems, culturally acceptable, accessible, economically fair and affordable; nutritionally adequate, safe and healthy; while optimizing natural and human resources.’