This report characterizes the difference in food purchase quality of low-income food insecure and food-secure households using the National Household Food Acquisition and Purchase Survey (FoodAPS), a unique data collection fielded by the USDA, Economic Research Service in partnership with the USDA, Food and Nutrition Service focused on household food purchase behavior. FoodAPS collected food acquisition and purchase data from 4,826 households over a single week between April 2012 and January 2013. The survey measured food insecurity using the 10-item, 30-day food security module, a series of questions that focus on behaviors and conditions related to adequate food supplies in the household. There are salient differences in overall quality of total food acquisitions, measured by the 2010 Healthy Eating Index score, purchased by food-secure and food-insecure households at or below 130 percent of the Federal poverty line. There are particularly important differences in total fruit, whole fruit, as well as total protein and seafood and plant protein foods purchased for these households. Moreover, food-insecure households spend less per adult equivalent on all food, but food at home in particular. Additionally, there are significant differences in dietary components not purchased or purchased in excess by these households: food-insecure households are much more likely to have no fruit, dairy, or protein, but large amounts of refined grains in their total purchase basket. Taking food spending and purchase quality into account, food-insecure households purchase about half of the fruit per adult equivalent and about three-fifths of the protein foods per adult equivalent in comparison with food-secure households.