FIGURE 3-1 Per capita total grain availability, 1970-2005.
NOTE: Data for 2005 based on a 2,000-calorie diet.
SOURCE: Wells and Buzby, 2008. USDA, ERS Food Availability (per capita) Data System.
FIGURE 3-2 Increase in average daily per capita energy (calorie) availability in the United States between 1970 and 2009.
SOURCE: Data from ERS, 2012. ERS Food Availability (per capita) Data System, adjusted for spoilage and other waste.
the composition of foods available. In particular, over the past four decades, production and availability have increased for grains more than for other types of foods. Grains of all types—including wheat, corn, rice, and oats—have become more readily available in the food supply. Total grain availability per person increased from 137 pounds in 1970 to 192 pounds in 2005 (Wells and Buzby, 2008; see Figure 3-1).
According to a 2008 U.S. Department of Agriculture (USDA) report on the major trends in food availability,1 not only did the availability of grains increase by 41 percent from 1970 to 2005, but the availability of all major food groups increased as well—fruits and vegetables (by 19 percent); meat, eggs, and nuts (8 percent); and milk/dairy products (6 percent). In addition, availability increased for fats and oils (62 percent) and added sugars and sweeteners (19 percent) (Wells and Buzby, 2008). As a result of increased production of grains and other foods, per capita total energy availability has risen substantially during the last 30 years—from 2,169 to 2,594 calories between 1970 and 2009 (Figure 3-2), with the largest proportion of the increase coming from fats and processed grain products (ERS, 2012). On the other hand, per capita availability of vegetables, fruits, and dairy products currently is less than 70 percent of the recommended amounts (Figure 3-3).
These aggregate production numbers may simply reflect Americans’ consumption preferences and choices. If so, then if the U.S. population were to make healthier choices, that change might be reflected in the aggregate production numbers. Alternatively, people may eat what is available. In this case, if the overall availability of different types of foods is inconsistent with current dietary recommendations—as the evidence suggests—individuals are unlikely to be able to meet the recommendations.
Food Purchasing Patterns
As discussed in Chapter 1, dietary intake is complex and multi-dimensional and includes food preferences, cultural appropriateness, preparation methods, meal patterns, and individual health needs, among other components. The following section reviews evidence on overall expenditures on food, the marginal propensity to consume food, where SNAP
1Food availability is defined as the total amount of food available for consumption and is calculated as the sum of annual production, beginning stocks, and imports minus exports, ending stocks, and nonfood uses.