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Center for Public Health Nutrition, University of Washington, Seattle, WA 98195
2To whom correspondence should be addressed. E-mail: adamdrew{at}u.washington.edu.
| ABSTRACT |
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KEY WORDS: incomes diet structure sugar fat energy costs obesity
Rates of obesity and overweight in the United States have risen sharply over the past two decades (1 ). Because the genetic pool has remained stable, the explanation must involve altered eating habits or the increasingly sedentary lifestyles (2 ,3 ). The sharpest change in diet structure has involved added sugars and fat (4 ). Per capita availability of each has increased by at least 20% since 1977. Nutritionists have blamed the current obesity epidemic on excessive consumption of fast foods, snacks (5 ) and soft drinks (6 8 ) and the elevated energy density of the U.S. diet. Strategies for obesity prevention increasingly focus on fiscal and policy measures to limit the consumption of fats and sweets (9 ,10 ).
Obesity in the United States is a public health problem with many social and economic antecedents. Far from being a random "genetic lottery," the burden of obesity and diabetes falls disproportionately on minorities and the poor. The economics of food choice may help explain why low income families have the highest rates of overweight. That explanation is based in part on high palatability and low energy cost ($/MJ) of added sugars and fats.
Fats and sweets are among the most palatable of foods (11 ,12 ). Animal studies show that prolonged consumption of fats and sweets may permanently affect the metabolic mechanisms of reward (11 ). Consumer food choices are shaped by taste, cost and convenience (13 ) and are predicted by past food purchases and eating habits. Fats and sweets provided in the form of snacks, beverages or fast foods are palatable, convenient and easy to use. Most important, their energy cost relative to other foods is low (14 ). Fats and sweets can be treated as an example of endogenous preferences in any economic model of consumer behavior.
The notion of endogenous preferences can be difficult to accommodate within the current economic theory. Much of traditional economics is based on the premise that rising prices will lead to decreased demand. The law of demand is behind current suggestions to augment the price of fats and sweets so consumers may allocate their resources toward the purchase of healthier foods (9 ,10 ). However, as suggested later, fats and sweets may prove to be an exception to the rule.
| Energy costs of sugar and fat |
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Even though the cost of raw ingredients is rarely linked to retail food prices, energy cost of fats and sweets at the apex of the Food Guide Pyramid is low (16
). Energy cost of potato chips is in the order of $2.00/10 MJ, and that for soft drinks is $2.20$3.70/10 MJ. In contrast, energy cost is
$9.50/10 MJ for fresh carrots and
$14.00/10 MJ for frozen orange juice. This differential in energy costs is compounded by price increases. Retail price increases between 1982 and 1997 were lower for sugar/sweets (52%) and fats and oils (47%) than for vegetables and fruit (93%) (16
). Not surprisingly, given the hierarchy of food prices, annual per capita consumption of sugar and fat remains near record-high levels (4
). Added sugars and fats now account for >50% of energy in the typical American diet (4
).
| Engels law and diet structure |
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| Incomes and diets in the United States |
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Consumers spending the highest proportion of disposable income on food (i.e., low income consumers) may also derive most dietary energy from sugar and fat. For low income families, obtaining sufficient dietary energy at low cost is the overwhelming concern. Food Stamp Program (FSP) participants reported that food price was the most important consideration in making food choices and that "the most important factor in choosing and preparing foods was to ensure that no-one would complain they are still hungry" (22 ). Diets of low income consumers for whom food price is the most important consideration may be high in sugars and fat, simply because these are the cheapest sources of dietary energy available.
| Poverty and obesity |
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| Obesity: an economic hypothesis |
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Americans have become more obese as the percentage of fat in the diet declined (28 ). An analogous point can be made with regard to diet costs. Americans are becoming more obese while spending a lower share of disposable income on food (Fig. 4 ). The amount of sugar and fat in the typical diet continues to rise. As primary prevention strategies related to nutrition, obesity and diabetes are put in place, lower socioeconomic groups continue to lag behind (29 ). There is support for the argument that obesity in the United States is not primarily a medical problem and cannot be controlled by primarily medical approaches (30 ).
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| FOOTNOTES |
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3 Abbreviations used: ERS, Economic Research Service; GDP, gross domestic product; USDA, U.S. Department of Agriculture. ![]()
| LITERATURE CITED |
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1. National Institutes of Health, National Heart, Lung, and Blood Institute (1998) Clinical guidelines on the identification, evaluation and treatment of overweight and obesity in adultsthe evidence report. Obes. Res. 6(suppl 2):1S-209S.
2. French, S. A., Story, M. & Jeffery, R. W. (2001) Environmental influences on eating and physical activity. Annu. Rev. Public Health 22:309-335.[Medline]
3. Dietz, W. H. & Gortmaker, S. L. (2001) Preventing obesity in children and adolescents. Annu. Rev. Public Health 22:337-353.[Medline]
4. Frazao, E. eds. Americas eating habits: changes and consequences 1999 USDA/ERS Agri. Info. Bull. 750.
5. Zizza, C., Siega-Riz, A. M. & Popkin, B. M. (2001) Significant increase in young adults snacking between 19771978 and 19941996 represents a cause for concern!. Prev. Med. 32:303-310.[Medline]
6. Harnack, L., Stang, J. & Story, M. (1999) Soft drink consumption among US children and adolescents: nutritional consequences. J. Am. Diet. Assoc. 99:436-441.[Medline]
7. Ludwig, D. S., Peterson, K. E. & Gortmaker, S. L. (2001) Relation between consumption of sugar-sweetened drinks and childhood obesity: a prospective, observational analysis. Lancet 357:505-508.[Medline]
8. Kant, A. K. (2000) Consumption of energy-dense nutrient-poor foods by adult Americans: nutritional and health implications: the Third National Health and Nutrition Examination Survey, 198894. Am. J. Clin. Nutr. 72:929-936.
9. Swinburn, B. A., Caterson, I., Seidell, J. C., Dietz, W. H. & James, W. P. T. (2002) Diet, nutrition and the prevention of excess weight gain and obesity. Draft background paper for the WHO consultation on Diet, Nutrition and the Prevention of Chronic Disease 2002Available at www.who.int/hpr/nutrition/expertconsultationreport.
10. Jacobson, M. F. & Brownell, K. D. (2000) Small taxes on soft drinks and snack foods to promote health. Am. J. Public Health 90:854-857.
11. Levine, A. S., Kotz, C. M. & Gosnell, B. A. (2003) Sugars and fats: the neurobiology of preference. J. Nutr. 133(suppl):831S-834S.
12. Yanovski, S. (2003) Sugar and fat: cravings and aversions. J. Nutr. 133(suppl):835S-837S.
13. Glanz, K., Basil, M., Maibach, E., Goldberg, J. & Snyder, D. (1998) Why Americans eat what they do: taste, nutrition, cost, convenience and weight control as influences on food consumption. J. Am. Diet. Assoc. 98:1118-1126.[Medline]
14. Drewnowski, A. (2000) Nutrition transition and global dietary trends. Nutrition 16:486-487.[Medline]
15. Lakdawalla, D. & Philipson, T. (2002) The growth of obesity and technological change: a theoretical and empirical examination. NBER Working Paper 8946 2002Available at http://www.nber.org/papers/w8946.
16. Putnam, J. J. & Allshouse, J. E. (1999) Food consumption, prices, and expenditures, 197097 1999 Food and Rural Economic Division, Economic Research Service. USDA Stat. Bull 965.
17. Meade, B. & Rosen, S. (1996) Income and diet differences greatly affect food spending around the globe. Food Rev. 4:39-44.
18. Drewnowski, A. & Popkin, B. M. (1997) Dietary fats and the nutrition transition: new trends in the global diet. Nutr. Rev. 55:31-43.[Medline]
19. Wilde, P. E., McNamara, P. E. & Ranney, C. K. (2000) The effect on dietary quality of participation in the food stamp and WIC programs. USDA/ERS FANR Report No. 9 2000.
20. Grant, D. K. & Maxwell, S. (1999) Food coping strategies: a century on from Rowntree. Nutr. Health 13:45-60.[Medline]
21. Lutz, S. M., Blaylock, J. R. & Smallwood, D. M. (1993) Household characteristics affect food choices. Food Rev. 16:12-18.
22. Basiotis, P. P., Kramer-LeBlanc, C. S. & Kennedy, E. T. (1998) Maintaining nutrition security and diet quality: the role of the Food Stamp Program and WIC. Fam. Econ. Nutr. Rev. 11:4-16.
23. Alaimo, K., Briefel, R. R., Frongillo, E. A. & Olson, C. M. (1998) Food insufficiency exists in the United States: results from the Third National Health and Nutrition Examination Survey (NHANES III). Am. J. Public Health 88:419-426.
24. Olson, C. M. (1999) Nutrition and health outcomes associated with food insecurity and hunger. J. Nutr. 129(suppl):521S-524S.
25. Rose, D. (1999) Economic determinants and dietary consequences of food insecurity in the United States. J. Nutr. 129:517-520.
26. Basiotis, P. P. & Lino, M. (2002) Food insufficiency and prevalence of overweight among adult women. Nutrition Insight No. 26 2002.
27. Darmon, N., Ferguson, E. L. & Briend, A. (2002) The adverse effect of a cost constraint on food selection and nutrient density: an analysis of human diets by linear programming. J. Nutr. 132:3764-3771.
28. Willett, W. C. (1998) Is dietary fat a major determinant of body fat?. Am. J. Clin. Nutr. 67(suppl):566S-562S.
29. James, W. P., Nelson, M., Ralph, A. & Leather, S. (1997) Socioeconomic determinants of health: the contribution of nutrition to inequalities in health. Br. Med. J. 24:1545-1549.
30. Kumanyika, S. K. (2001) Minisymposium on obesity: overview and some strategic considerations. Annu. Rev. Public Health 22:293-308.[Medline]
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