Drewnowski et al.1 aim to explore the complex relationship between obesity and accessibility of healthy foods on the basis of proximity and price. Their finding that obesity rates were three times higher in those that shopped at low-cost as opposed to high-cost supermarkets persisted even after adjustment for socioeconomic status. While their results do not necessarily indicate causality, they are consistent with other evidence suggesting a link between consumption of low-cost, high-calorie processed foods and obesity.2
Such findings are worth considering in the context of predictions regarding food security in response to climate change. Much of the discussion regarding the effects of climate change on food has focused on declining food production threatening food security in vulnerable areas, particularly in developing countries in which undernutrition is already a concern.3 However, a paradox has been recognized in which food insecurity in developed countries is often associated with increasing risk of obesity rather than undernutrition.4
This paradox may be explained by the relationship between climate change and food price. For example, Australian studies have demonstrated that drought events will lead to increased price of most foods, but that fresh fruit and vegetables are disproportionately affected.5 By contrast, the price of processed foods is less affected, and in some cases processed foods may even reduce in cost.6 Evidence suggests that when food prices increase, vulnerable groups begin to shift their consumption to favor low-cost, high-calorie foods because these are relatively more affordable than healthier fresh foods.4 In one Australian study, obesity rates were 20% to 40% higher in women experiencing food insecurity.7
The net result of such changes is an increasing inequity of access to healthy foods. In contrast to developing regions, outcomes in developed countries are more likely to include increasing rates of obesity and associated chronic diseases, particularly in those individuals of lower socioeconomic status.8 The findings of Drewnowski et al. support a central role of food price in determining obesity risk, presumably as a result of influencing dietary habits. The effects of climate change are likely to exacerbate this problem in developed countries. Further investigation of the link between climate change, food price, and obesity are therefore warranted, and adaptation strategies are essential.
References
- 1.Drewnowski A, Aggarwal A, Hurvitz P, Mosivais P, Moudon A. Obesity and supermarket access: proximity or price? Am J Public Health. 2012;102(8):e74–e80 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.McMichael AJ, Powles J, Butler C, Uauy R. Food, livestock production, energy, climate change, and health. Lancet. 2007;370(9594):1253–1263 [DOI] [PubMed] [Google Scholar]
- 3.Rosenzweig C, Parry ML. Potential impact of climate change on world food supply. Nature. 1994;367:133–138 [Google Scholar]
- 4.Burns C. A Review of the Literature Describing the Link Between Poverty, Food Insecurity and Obesity With Specific Reference to Australia. Melbourne, Australia: VicHealth; 2004 [Google Scholar]
- 5.Quiggin J. Drought, climate change and food prices in Australia. Available at: http://www.acfonline.org.au/sites/default/files/resources/Climate_change_and_food_prices_in_Australia.pdf. Accessed October 15, 2012
- 6.Queensland Health. The 2004 Healthy Food Basket (HFAB) Survey. Brisbane, Australia: Queensland Government; 2006 [Google Scholar]
- 7.Kettings C, Sinclair A, Voevodin M. A healthy diet consistent with Australian health recommendations is too expensive for welfare-dependent families. Aust N Z J Public Health. 2009;33(6):566–572 [DOI] [PubMed] [Google Scholar]
- 8.Edwards F, Dixon J, Friel Set al. Climate change adaptation at the intersection of food and health. Asia Pac J Public Health. 2011;23(2 suppl):91S–104S [DOI] [PubMed] [Google Scholar]