Over the past 20 years, some store formats, including supercenters, dollar stores and warehouse club stores have increased their share of Americans’ spending on “at-home food”—food and beverages purchased from retail stores as opposed to away-from-home eateries. In 1994, conventional supermarkets accounted for 75.9% of at-home food sales, whereas supercenters and warehouse club stores accounted for 3%. By 2014, supermarkets’ share of at-home food sales fell to 64.9%, while supercenters’ and warehouse club stores’ share rose to 16.5%.

A study produced by USDA’s Economic Research Service (ERS) used household purchasing data to compute “healthy basket” scores for the foods and beverages purchased each month by a household. Scores were highest for warehouse club stores (8.3), supermarkets (8.2) and supercenters (8.0). Healthful foods recommended for increased consumption, such as dark green vegetables, whole fruits and low-fat dairy products, scooped up a larger share of total food purchases from these store formats than from other formats. Mass merchandisers followed with a score of 6.2.

The higher the score, the closer the household’s purchases aligned with healthy-diet expenditure shares informed by the food categories and recommendations outlined in USDA’s Low-Cost, Moderate-Cost and Liberal Food Plans, which represent a nutritious diet at three different cost levels. Monthly food shopping baskets were categorized by the dominant store format, accounting for the household’s largest share of food expenditures. Household food baskets dominated by purchases from drug stores, convenience stores and dollar stores had the least healthful purchases. Drug stores, convenience stores and dollar stores accounted for the largest shares of the least healthful foods, such as soft drinks and sugar, sweets and candies. The average score for convenience store baskets was half that for warehouse club store baskets.

Over 2008-12, an average of 67% of households predominantly shopped at supermarkets, 17% at supercenters, 6% at warehouse club stores and 2% at mass merchandisers. The other 8% shopped predominately at smaller formats—drug, dollar, convenience and other store formats. Households that regularly shop at multiple formats within a given month may skew overall scores for certain format types because all food purchases are assigned to the dominant store format. However, these households account for fewer than 25% of the households analyzed in the study.