Energy Density and Cost of Foods in Germany
- 15.03.2013
- English Articles
- Joachim Westenhöfer
Peer-reviewed | Manuscript received: October 2, 2012 | Revision accepted: January 1, 2013
Introduction
According to representative surveys performed by the Robert Koch Institute (RKI) in 2010, 16.1 % of adult men and 15.6 % of adult women in Germany are obese. The corresponding figures in the 2009 Microcensus are 15.7 % for men and 13.8 % for women [1]. These two studies also recorded 44 % overweight men and 29 % overweight women.
The RKI Study on Adult Health in Germany (DEGS1) [2] not only queried weight and height between 2008 and 2011, but also measured these parameters. The prevalence of obesity was as high as 23.3 % in men and 23.9 % in women [1]. On the basis of data collected in 2005 and 2006, the National Consumption Study II found that 20.5 % of men and 21.2 % of women were obese [3]. Obesity is one of the most important public health problems in Germany, in view of the diseases it accompanies or causes.
Summary
There is considerable evidence that low socio-economic status is associated with a higher prevalence of obesity. It was hypothesized that foods with higher energy density (kcal/100 g) have lower energy costs (price per kcal) than foods with lower energy density. Therefore a low disposable income could contribute to the preferred consumption of foods with high energy density. Thus energy requirements can be met with relatively little money. Data on energy costs and energy density of foods from different countries support this hypothesis. For Germany, no systematic data on this relationship is available.
Prices and package sizes of 602 foods from 9 different food groups (fruit, vegetables, noodles-rice-bread, meat, meat products, milk and milk products, fats, sweets and nibbles, convenience foods) were recorded in supermarkets and shops (bakeries, butchers). Energy content was also recorded, if this was listed on the package, or obtained from nutrient databases if necessary. Energy density was calculated as kcal per 100 g. Energy costs were calculated as 5 per 100 kcal. Energy costs correlated negatively with energy density (r = -0.57, p < 0.001) over all 602 food samples.
In addition, there was a significant negative correlation within most food groups. In Germany, as in other countries, foods with high energy density are relatively cheap. Therefore, economic constraints make it likely that food of high energy density is preferably consumed in low income groups, contributing to excessive energy intake.
Keywords: Energy density, food costs, obesity, income, energy content
