Trends in US home food preparation and consumption: analysis of national nutrition surveys and time use studies from 1965-1966 to 2007-2008

Abstract

Background: It has been well-documented that Americans have shifted towards eating out more and cooking at home less. However, little is known about whether these trends have continued into the 21st century, and whether these trends are consistent amongst low-income individuals, who are increasingly the target of public health programs that promote home cooking. The objective of this study is to examine how patterns of home cooking and home food consumption have changed from 1965 to 2008 by socio-demographic groups.

Methods: This is a cross-sectional analysis of data from 6 nationally representative US dietary surveys and 6 US time-use studies conducted between 1965 and 2008. Subjects are adults aged 19 to 60 years (n= 38,565 for dietary surveys and n=55,424 for time-use surveys). Weighted means of daily energy intake by food source, proportion who cooked, and time spent cooking were analyzed for trends from 1965-1966 to 2007-2008 by gender and income. T-tests were conducted to determine statistical differences over time.

Results: The percentage of daily energy consumed from home food sources and time spent in food preparation decreased significantly for all socioeconomic groups between 1965-1966 and 2007-2008 (p ≤ 0.001), with the largest declines occurring between 1965 and 1992. In 2007-2008, foods from the home supply accounted for 65 to 72% of total daily energy, with 54 to 57% reporting cooking activities. The low income group showed the greatest decline in the proportion cooking, but consumed more daily energy from home sources and spent more time cooking than high income individuals in 2007-2008 (p ≤ 0.001).

Conclusions: US adults have decreased consumption of foods from the home supply and reduced time spent cooking since 1965, but this trend appears to have leveled off, with no substantial decrease occurring after the mid-1990's. Across socioeconomic groups, people consume the majority of daily energy from the home food supply, yet only slightly more than half spend any time cooking on a given day. Efforts to boost the healthfulness of the US diet should focus on promoting the preparation of healthy foods at home while incorporating limits on time available for cooking.

Figure 1

Daily energy intake of US adults by food source, 1965-1966 to 2007-2008. Data sources: Household Food Consumption Survey (HFCS) of 1965–1966 (n=4,114), Nationwide Food Consumption Survey (NFCS) of 1977–1978 (n=12,935), Continuing Survey of Food Intakes by Individuals (CSFII) of 1989–1991 (n=7,750), CSFII of 1994–1996 (n=6,894), National Health and Nutrition Examination Survey (NHANES) of 2003–2004 (n=3,138), and NHANES of 2007–2008 (n=3,734). ^* Percentage of calories eaten from home sources differed significantly from HFCS 1965–1966, p ≤ 0.01 (t-test). ^** Percentage of calories eaten from home sources differed significantly from previous survey, p ≤ 0.01 (t-test). ^*** Percentage of calories eaten from home sources differed significantly between low and high income groups for relevant survey year, p ≤ 0.01 (t-test).