ResearchCurrent ResearchThe Rising Cost of Low-Energy-Density Foods
Section snippets
Methods
The present study used a market-basket approach to assess the prices of foods. A market basket is simply a list of defined products in purchasable form. The same approach is used by the US Bureau of Labor Statistics in monitoring prices and inflation in goods and services as part of the Consumer Price Index. Previous research studies have used the market-basket method to assess the price and availability of food in different geographical areas (17).
Results
Food-price collection methods were highly reliable in the 2 years of the present study. Figure 1 illustrates the relationship between food prices collected ($/100 g) in 2004 and in 2006 for the same 372 foods. There was a strong correlation between 2004 and 2006 prices (r2=0.95), and the average price increase calculated for all foods and beverages was 7.9%.
Discussion
Improving the nutrients-to-energy ratio in the American diet is the stated goal of the 2005 Dietary Guidelines for Americans and the 2005 US Department of Agriculture’s MyPyramid (22, 23). Many studies have provided ample evidence to justify the adoption of lower-energy-density but high-quality diets (6, 7), whether for the purpose of weight management (8) or the prevention of chronic disease (24, 25). Few of those studies have addressed the issue of food prices and diet costs (16).
Being able
Limitations of the Present Study
The present analyses were based on prices collected from only three major supermarket chains in a single, major US metropolitan area, and thus cannot account for geographic variation in prices or in inflationary trends (33). In addition, each food and beverage was priced using methods that did not take into account sale prices, loyalty-card discounts, coupons, or other shopping strategies that can help consumers control food expenditures (34). Moreover, the particular group of foods or “market
Conclusions
The sharp price increase observed for vegetables and fruit relative to fats and sweets suggests that the ability to adopt more-healthful diets may be limited by economic constraints. Although low-energy-density foods are undoubtedly associated with better health outcomes, they are also more costly (9, 36) and tend to be purchased by the more-affluent consumer (37). The energy density of the American diet is reported to have risen (38), suggesting that the consumer is seeking out lower-cost
P. Monsivais is a research fellow in the Nutritional Sciences Program, School of Public Health and Community Medicine and the Department of Dental Public Health Sciences, School of Dentistry, University of Washington, Seattle.
References (41)
- et al.
A cost constraint alone has adverse effects on food selection and nutrient density: An analysis of human diets by linear programming
J Nutr
(2002) - et al.
Low-energy-density diets are associated with high diet quality in adults in the United States
J Am Diet Assoc
(2006) - et al.
Dietary energy density is associated with energy intake and weight status in US adults
Am J Clin Nutr
(2006) - et al.
Poverty and obesity: The role of energy density and energy costs
Am J Clin Nutr
(2004) Obesity and the food environment: Dietary energy density and diet costs
Am J Prev Med
(2004)- et al.
The economics of obesity: Dietary energy density and energy cost
Am J Clin Nutr
(2005) - et al.
Low-energy-density diets are associated with higher diet quality and higher diet costs in French adults
J Am Diet Assoc
(2007) - et al.
Body mass index in elementary school children, metropolitan area food prices and food outlet density
Public Health
(2005) Examining energy density: Comments on diet quality, dietary advice, and the cost of healthful eating
J Am Diet Assoc
(2006)- et al.
Serum concentrations of retinal, alpha-tocopherol and the carotenoids are influenced by diet, race and obesity in a sample of healthy adolescents
J Nutr
(2001)
Measurement characteristics of the Women’s Health Initiative food frequency questionnaire
Ann Epidemiol
Association between dietary patterns and plasma biomarkers of obesity and cardiovascular disease risk
Am J Clin Nutr
Dietary patterns and health outcomes
J Am Diet Assoc
Food choices and diet costs: An economic analysis
J Nutr
A nutrient density standard for vegetables and fruits: Nutrients per calorie and nutrients per unit cost
J Am Diet Assoc
Do economic constraints encourage the selection of energy dense diets?
Appetite
Secular trends in patterns of self-reported food consumption of adult Americans: NHANES 1971-1975 to NHANES 1999-2002
Am J Clin Nutr
Low-cost diets: More energy, fewer nutrients
Eur J Clin Nutr
The role of energy density
Lipids
Energy-dense diets are associated with lower diet costs: A community study of French adults
Public Health Nutr
Cited by (0)
P. Monsivais is a research fellow in the Nutritional Sciences Program, School of Public Health and Community Medicine and the Department of Dental Public Health Sciences, School of Dentistry, University of Washington, Seattle.
A. Drewnowski is professor and director, Nutritional Sciences Program, School of Public Health and Community Medicine, University of Washington, Seattle.