This analysis is the first to examine trends in the U.S. food supply using an index of dietary quality. Although the HEI-2005 was designed to measure adherence to the 2005 Guidelines, those Guidelines deviate only modestly in degree—and not in direction—from past editions. According to this analysis, the country's food supply has been failing to provide diets consistent with Federal recommendations on a number of key components for the past several decades. Specifically, while meats and total grains have been supplied generally in recommended proportions; total vegetables, total fruit, whole fruit, and milk/milk alternates each have been supplied at roughly half the recommended level, proportions that changed very little over time; and saturated fat, sodium and calories from SoFAAS have been supplied in varying degrees of unhealthy abundance over the years. Supplies of dark-green vegetables, orange vegetables, legumes and whole grains have been entirely insufficient relative to recommendations, with virtually no change over time.
There are limitations to the food supply data in their ability to account precisely for certain of the HEI-2005 components.13
However, all of the issues are assumed to represent minor limitations which would affect scores only slightly one way or the other.
For the purposes of this study, the advantages of the data are several. First, the food supply data provide a valuable lens through which to examine how well the macro food environment in this country conforms to the recommendations embodied in the Guidelines. Second, the generally clean separation among commodities makes analysis relatively simple (compared to, say, reported individual-level intakes). And finally, because the methods used to derive the food supply data are employed consistently over time, they are ideal for assessing trends.
Previous analyses of food supply data in relation to dietary guidance, using absolute amounts rather than an index measure, derived similar conclusions.20–25
Comparing food supply data to USDA's Food Guide Pyramid recommendations up through the mid 1990s, Young and Kantor found particularly large discrepancies for added sugars, fats and oils, fruits, and certain vegetables—notably dark-green vegetables, orange vegetables and legumes.25
They also identified the agricultural implications of addressing these imbalances, which included extensive shifts in production, trade and prices. Other analyses also have projected dramatic agricultural adjustments to bring the food supply into conformance with Federal dietary guidance.21–24
Moreover, the results of the current analysis are consistent with recent assessments of individual diets in relation to the Guidelines
Guenther et al applied the HEI-2005 to data from the 2003–04 National Health and Nutrition Examination Survey.26
They found average diets to score 57.5 overall, similar to what was found in the current study for the food supply during the same period. Regarding the components, individual diets scored somewhat lower than the food supply on Oils and Calories from SoFAAS and higher on Milk, Saturated Fat, and Sodium (although salt added at the table was not ascertained in that analysis). Recent analyses of the distribution of usual intake of various foods in the U.S. population noted that, across nearly all age/gender groups, 95% of the population is not consuming enough dark-green vegetables, orange vegetables, legumes or whole grains, and 95% of adult women are not consuming the recommended amounts of milk.27
A quarter of the U.S. population consumes more than 1000 kcal per day from added sugars, solid fats, and alcoholic beverages.28
The HEI-2005 is a measure of diet quality, not quantity, which means it cannot ascertain whether the food supply provides the right amount of energy for the population. However, the rates of obesity and overweight in this country certainly indicate there is an overabundance of energy available for consumption relative to the amount the population expends. Sacks and Swinburn have estimated this to be 350 calories per day for children and 500 calories per day for adults.29
Although this estimate is the subject of some debate, 500 kcal/person/day is roughly the size of the increase in energy available in the loss-adjusted food supply between 1970 and 2007, a period in which obesity rates doubled for adults and tripled for children.30
Calories from SoFAAS are most dispensable, as SoFAAS provide very little else nutritionally. But simply removing SoFAAS is not sufficient to produce a food supply supportive of the dietary recommendations. In order for the loss-adjusted food supply to decrease by 500 kcal/person/day and achieve optimal HEI-2005 scores, the following changes would be necessary:
- Calories from SoFAAS would need to decrease by 61%, including about 120 kcal of solid fat. This would reduce the overall energy available, make room for increased energy to be supplied by added fruits, vegetables, and milk, and reduce both saturated fat and calories from SoFAAS.
- The supply of fruit would need to more than double, with most of that being whole fruit rather than juice.
- The supply of vegetables would need to increase by 70%, with nearly all of the increase coming from dark-green vegetables, orange vegetables and legumes.
- Total grain supply could remain about constant, but four times as much of the grain should remain as whole grain, not be refined.
- Milk supply would need to increase about 70%, but virtually all of the increase would need to come from fat-reduced milk, milk products or fortified soy beverages
- Salt added to foods (in processing, cooking and at the table) would need to decrease by over half.
Although some aspects of the food supply—notably salt, fat, and added sugars—may have shifted in response to dietary recommendations, albeit temporarily, others have changed hardly at all. The supply of salt declined slightly for a few years, only to increase again. Saturated fat (and consequently, calories from solid fat) in the food supply fluctuated over the years, sometimes decreasing only when calories from added sugars were increasing. These trends may be the result of issues that receive more or less attention over time. Processed foods are major sources of salt, fat and sugars in the U.S. diet,33,34
because these ingredients contribute to the taste, mouth feel, and shelf life of foods. The food industry responds to food fads by altering the relative amounts of these ingredients in an effort to market the “healthfulness” of their products, but sometimes they simply replace one ingredient with another. For example, low-fat cookies and other sweets were popular in the 1990s, but these “guilt-free” alternatives were frequently no lower in calories than their full-fat counterparts, because the fat was replaced with added sugars.35
The Dietary Guidelines for Americans
serve as a statement of Federal nutrition policy while focusing almost exclusively on educational activities to guide consumers to make healthy choices. Although the Guidelines
have been available for several decades, there is no clear evidence they have improved the U.S. diet. A wealth of behavioral research suggests this may be because educating individuals is not sufficient to produce change. Rather, a comprehensive approach involving action at all levels of the socio-ecologic spectrum is needed,10
including structural changes in the food supply. Such an approach was recommended to address inactivity in the government's first-ever Physical Activity Guidelines for Americans
released last year.37
The amounts and types of food available in the nation's food supply data reflect the economic balance among forces that both “push” and “pull” foods through distribution channels. Consumer demand exerts the “pull,” and agriculture and economic policies and industrial marketing efforts provide the “push.” Indeed, according to the U.S. Department of Agriculture, the purposes of the Loss-Adjusted Food Supply Data are to monitor the potential of the food supply to meet the nutritional needs of the U.S. populations, translate nutrition goals for Americans into food production and supply goals, and evaluate the effects of marketing practices over time.15
When applied to those purposes, as in this analysis, the data suggest it may be unrealistic to expect a groundswell in consumer demand that would be sufficient to “pull” a healthy food supply through distribution channels. Rather, deliberate efforts on the part of policymakers and industry may be necessary to provide a supply of foods consistent with nutrition recommendations and make healthy choices available to all.10