Why Are Americans Consuming Less Fluid Milk? A Look at Generational Differences in Intake Frequency
by Hayden Stewart
, Diansheng Dong
, and Andrea Carlson
Economic Research Report No. (ERR-149) 35 pp, May 2013
What Is the Issue?
Most Americans do not consume enough dairy products. The Dietary Guidelines for Americans, 2010 recommends 2 cup-equivalents per day for children aged 2 to 3 years, 2.5 for those aged 4 to 8 years, and 3 for Americans older than age 8. However, per capita dairy consumption has long held steady at about 1.5 cup-equivalents, despite rising cheese consumption. This stasis in per capita dairy consumption results directly from the fact that Americans are drinking progressively less fluid milk. Since 1970 alone, per capita fluid milk consumption has fallen from 0.96 cup-equivalents to about 0.61 cup-equivalents per day.
The Federal Government encourages dairy consumption, including fluid milk, cheese, and yogurt, among other foods, through the Dietary Guidelines for Americans, 2010. Special emphasis is placed on fat-free and low-fat products. USDA further supports this message through programs like the National School Lunch Program (NSLP). The NSLP stipulates that schools must provide fluid milk and it must be low-fat or skim, rather than whole. Dairy farmers and fluid milk processors are also working to promote dairy products. The popular “Got Milk?” campaign, for one, encourages drinking fluid milk.
This report examines trends in Americans’ fluid milk consumption, including average portion sizes and generational differences in the frequency of milk drinking, to investigate possible explanations for the continued decreases.
What Did the Study Find?
Data from USDA dietary intake surveys conducted between the 1970s and 2000s show that Americans—on occasions when they drink fluid milk—continue to consume about 1 cup (8 fluid ounces). Given the stability of portions, trends showing decreases in per capita consumption since the 1970s mainly reflect changes in consumption frequency. Between the 1970s and 2000s, people have become less apt to drink fluid milk at mealtimes, especially with midday and nighttime meals, reducing the total number of consumption occasions:
• Between surveys in 1977-78 and 2007-08, the share of preadolescent children who did not drink fluid milk on a given day rose from 12 percent to 24 percent, while the share that drank milk three or more times per day dropped from 31 to 18 percent.
• Between 1977-78 and 2007-08, the share of adolescents and adults who did not drink fluid milk on a given day rose from 41 percent to 54 percent, while the share that drank milk three or more times per day dropped from 13 to 4 percent.
Underlying these decreases in consumption frequency are differences in the habit to drink milk between newer and older generations. All else constant (e.g., race and income), succeeding generations of Americans born after the 1930s have consumed fluid milk less often than their preceding generations:
• Americans born in the early 1960s consume fluid milk on 1.1 fewer occasions per day than those born before 1930.
• Americans born in the early 1980s consume fluid milk on 0.3 fewer occasions per day than those born in the early 1960s.
Differences across the generations in fluid milk intake may help account for the observed decreases in per capita fluid milk consumption in recent decades despite public and private sector efforts to stem the decline. Furthermore, these differences will likely make it difficult to reverse current consumption trends. In fact, as newer generations replace older ones, the population’s average level of fluid milk consumption may continue to decline.
How Was the Study Conducted?
ERS researchers pooled data from five USDA dietary intake surveys for analysis. These included the 1977-78 Nationwide Food Consumption Survey, the 1989-1991 Continuing Survey of Food Intakes by Individuals (CSFII), 1994-1996 CSFII, the 2003-04 National Health and Nutrition Examination Survey (NHANES), and the 2007-08 NHANES. Respondents in each survey were asked to report their intake of all foods and beverages on one or more days. This study focused on individuals’ fluid milk consumption during a single, 24-hour period.
Researchers reviewed the existing literature on fluid milk demand, compared consumption data across periods in the different surveys, and then conducted a formal hypothesis test for whether newer generations are consuming fluid milk fewer times per day, and whether changes in portion sizes are also affecting consumption trends. This was accomplished by estimating an econometric model that predicts both the frequency and total quantity of fluid milk consumed by Americans who participated in USDA food consumption surveys, based on their birth year, race, household income, and demographic characteristics.