Food costs, diet quality and risk of disease

Australia and the world once again is facing uncertain economic times, and nutrition professionals should not lose sight of the impacts of this on food security and the nutritional health of our vulnerable communities. Food insecurity, running out of food and not having sufficient money to buy more, affects more than 5% of Australian households (>1.1 million Australians) and is higher in some groups, including single-parent households with dependent children.1 Access to sufficient food will be exacerbated by soaring global food prices.2 In Australia, food prices have increased over the past year by >6%, with rises in 15 out of 26 food categories. The prices of key components of a healthy diet, and of fruits and vegetables have been particularly affected, with rises of >66% and almost 10%, respectively.3 At the same time, prices for other household necessities, such as housing, fuel, and power also increased,3 putting greater pressure on household budgets, particularly for low-income groups. Money for food often comprises what remains after paying for other necessities.4 Low-income groups in Australia, therefore, are at increasing risk of food insecurity and this will have negative impacts on the quality of their diet. A clear relationship has been demonstrated between food costs, food purchasing and consumption, the nutritional quality of diets and excess weight.5 Studies in Australia6 and overseas consistently have found that healthier diets cost more4,7–10 and inversely, that lower diet costs are associated with higher energy and fewer nutrients.11 Low-income families are therefore likely to purchase high energy-dense but less healthy foods that are cheaper,12 potentially a key driver of the demonstrated relationship between food insecurity and overweight and obesity,13 and the high prevalence of obesity in low-income groups.14 Data from the USA also have shown an association between the increasing cost of fruit and vegetables and childhood obesity.15 The prevalence of overweight and obesity has been increasing worldwide,16 including in Australia.17 The consistent association of overweight and obesity with mortality, disability and decreased health-related quality of life16,18 as well as recognition of the high economic cost of obesity19 has lead to its identification as a priority area for preventive health action in Australia. The link between food prices and overweight necessitates greater recognition of the importance of food costs as a key determinant of health. Vulnerable and low-income groups who are more price susceptible need to spend more of their income to purchase ‘a healthy food basket’, than unhealthy foods.4,7,20 The recent study by Wong and colleagues6 in South Australia, showed that low-income families would have spent 28–34% of their income on a ‘healthy food basket’, compared with 6–9% for high-income families. While the affordability of healthy food for families on average household income in Australia has not changed markedly in the last decade,21 healthy food clearly has become less affordable for low-income groups. Food choices are not just about nutrition, but also are part of social and cultural identities. It is recognised that healthy foods and a healthy diet can be purchased for less by substituting low-cost brands, purchasing inexpensive but nourishing foods such as milk powder or inexpensive meat cuts, substituting cheaper plant-based foods for animal foods and through other food-substitution strategies.21,22 Explanations of failures by low-income families to purchase and prepare meals based on these cheaper food options could be constructed in terms of poor knowledge, motivation or bad lifestyle choice. However, recent US studies suggest that minimising the costs of a healthy diet through food substitutions resulted in loss of variety and also in meals that differed greatly from normal social patterns.22,23 The importance of social and cultural patterns of food consumption needs to be considered in strategies to promote healthy food consumption, in the context of increasing food prices. While the focus on healthy diets in relation to food choices and food costs has largely been on the association with overweight and obesity in developed countries, the consequences of rising food prices globally has wider impacts in developing countries. As well as having to manage the increasing impact of overweight and obesity and associated chronic disease, poorer countries also are experiencing malnutrition linked to insufficient food and kilojoules. In South Africa, for example, nutritional surveys have shown that levels of vitamin A and iron deficiency among children increased between 1995 and 2005, and intakes of vitamin A, B6, riboflavin, niacin, folic acid, calcium, iron and zinc decreased. The situation is likely to have worsened as a result of rapidly increasing food prices, with the consumption of a nutritionally adequate diet out of reach of most poor households, who comprise the majority of the population.24 Globally, Food and Agriculture Organization of the United Nations has indicated that the rate of reduction of undernourished people has fallen short of what is required to reach the Millennium Development Goals of halving the number of malnourished people by 2015,25 and is likely to be worsened by soaring global food prices. Health professionals need to take the opportunity presented by the current discussions to develop a National Food Plan to highlight the important links between food prices and health and to identify the essential strategies needed to address this important issue. More research in Australian contexts aimed at understanding the relationship between food costs, food expenditure and chronic disease is urgently required, as most data come from overseas studies. Consideration should be directed to the appropriateness in different geographic and cultural settings in Australia of measures such as the ‘healthy food basket’ to monitor ongoing impacts of our fluctuating economic environment on diet quality and health. Regular monitoring of the nutritional status of the Australian population needs to incorporate monitoring of the cost of a healthy diet in Australia. In particular, the proposed National Food Plan needs to have a clear focus on the importance of food costs and food accessibility on the health of disadvantaged and vulnerable groups. This will be Australia's first National Food Plan, and it will be up to health professionals to ensure that a health and equity focus is at its core.