This post is part of the Science Tuesday feature series on the USDA blog. Check back each week as we showcase stories and news from USDA’s rich science and research portfolio.
Many of our diets aren’t what they should be. Americans eat fewer fruits and vegetables than Federal nutrition guidance recommends, and we over-consume fats, added sugars, and refined grains. Health professionals warn us that the less-healthful food choices are showing up on our waistlines and in our health, contributing to increasing cases of overweight and obesity, cardiovascular disease, and diabetes. Knowing how far we stray from good dietary patterns, and whether the diets of certain segments of the population are more misaligned, can help in designing more effective programs and consumer education.
Along with my colleagues at USDA’s Economic Research Service (ERS), I wanted to see how well the choices people make at the grocery store match Federal dietary recommendations. We looked at grocery store purchases of Nielsen Homescan “panelists” from 1998 to 2006. The Homescan panelists are a nationally-representative sample of U.S. households who are asked to record their food and beverage purchases from all retail stores. We compared these purchases to USDA-recommended food spending guidelines, which indicate how to allocate food budgets on 23 broad categories to meet the Dietary Guidelines for Americans.
Consumer spending came close to matching USDA recommendations for only 1 of the 23 food categories—potatoes—under-spending on the other vegetable categories. For example, households spent an average of only 0.5 percent of their food budgets during 1998-2006 on dark green vegetables compared with the recommended 7 percent. Households also under-spent on whole grains, whole fruit, lower-fat dairy, nuts, poultry, and fish, while they over-spent on other foods including refined grains, fruit juices, regular dairy products, and meats. Refined grains, for example—a category that includes non-whole grain crackers, cookies, breads, and pasta—accounted for 17 percent of the spending; the USDA spending guidelines recommend 5 percent.
There was some improvement between 1998 and 2006 in the healthfulness of the average food shopping basket. Households shifted from refined grains toward whole grains, but allocated less of their food budgets to fruits and vegetables and more to packaged and processed foods and beverages.
Diet quality is a general problem in America that’s not confined to a particular socio-demographic group. There’s room for improvement in food purchases across income levels, regions of the country, and racial groups. More information can be found in our report, Assessing the Healthfulness of Consumers’ Grocery Purchases.
