Food purchasing patterns in purchase-driven societies.

Since purchasing food is the primary if not exclusive means by which most of us obtain our food, an examination of food purchasing habits, especially in consumer-driven societies, is entirely appropriate. In this issue of Public Health Nutrition, two articles explore very different aspects of food purchasing habits. Using survey data from the Brisbane Food Study, Turrell and Kavanagh examine food purchasing behaviour in terms of what types of foods are purchased. Their analysis is a rare, hypothesis-driven examination of socio-economic differences in food purchasing behaviour. They found that participants of lower socio-economic position, as indicated by education and income, were less likely to buy foods that were high in fibre and low in fat, salt and sugar. These lesshealthy food selections may be the result of their having less knowledge of dietary recommendations and having more (possibly unjustified) food cost concerns. Not addressed in their analysis is how occupation, a third common indicator of socio-economic position that they mention, is related to food purchases, and whether occupation exerts its influence, as they suggest, through social norms. Still, their conclusions are sound: that disparities in dietary behaviours by socio-economic position persist, and, more importantly, that ‘populationwide approaches do not necessarily alter underlying dietary inequalities’. Dietary inequalities persist, I would add, because current, population-wide approaches do not address underlying socio-economic inequalities; in Tim Lang’s words, ‘Change society, and nutrition will follow’. Also in this issue, Yoo et al. use consumer-intercept interviews to examine a different, seldom examined aspect of food purchasing behaviour – frequency of shopping. They found that the most preferred shopping patterns were one big weekly or biweekly trip, supplemented with a few small trips during the week. Not surprisingly, the usual places to shop for such shoppers were large or very large markets. They also found that the strongest correlate of shopping pattern among the factors they examined was ethnicity – indirect evidence of the importance of cultural and social influences on shopping patterns. Of interest in the future will be investigations of how shopping patterns relate to dietary intake. Underlying both studies is the fact that both were set in purchaseor consumer-driven societies, in which what we eat is determined almost entirely by the relationship between the individual consumer and the supplier, including retailers and the food industry. The relationship ismorecomplex thanthe typicalconsumerrealises.Aweekly shopping trip to the supermarket seems innocent enough, until we consider the social, physical and economic environments that make supermarkets more desirable than street markets; that necessitate a weekly or biweekly drive to the supermarket; that make white bread more common than whole-grain bread in the marketplace; and that make snacks and high-fructose corn-syrup-sweetened beverages virtually essential components of our diet. The consumer–supplier relationship, in this case, is one in which the suppliers clearly have the greater amount of power, contrary to consumers’ perceptions. So many of our food purchases are determined by marketing and advertising, no matter how knowledgeable we are in dietary recommendations, and facilitated by a system that makes many foods too cheap to resist purchasing even when they are completely unnecessary, if not harmful. One aspect of food purchasing behaviour not addressed by these studies is what determines the purchase of unnecessary foods at any given shopping trip. In her book The Hungry Gene, for example, Ellen Ruppel Shell cites an estimate by marketing professor James U McNeal that ‘75 percent of spontaneous food purchases can be traced to a nagging child. And one out of two mothers will buy a food simply because her child requests it’. Such work traditionally falls into the area of marketing research, often for the benefit of the marketer/advertiser. It also falls well within the purview of the new nutrition science. It is necessary work if we want to understand more about how food purchasing behaviours relate to dietary intake and health, for the benefit of the public’s health. It is encouraging that both articles discussed above are one in a series of studies or of planned future studies in this area. This reflects a growing and continued interest in food purchasing habits and in how individuals as consumers interact with their food system. Investigations by nutrition scientists into the nature of the food consumer–food supplier relationship, whether defined according to what and how much food is selected for purchase, where foods are purchased or how often, are appropriate and long overdue.