BACKGROUND The Food and Drug Administration is considering changes to the Nutrition Facts label to help consumers make more healthful choices. OBJECTIVE To examine the effects of modifications to the Nutrition Facts label on foods that can be listed as having 1 or 2 servings per container, but are reasonably consumed at a single eating occasion. DESIGN Participants were randomly assigned to study conditions that varied on label format, product, and nutrition profile. Data were collected via an online consumer panel. PARTICIPANTS/SETTING Adults aged 18 years and older were recruited from Synovate's online household panel. Data were collected during August 2011. A total of 32,897 invitations were sent for a final sample of 9,493 interviews. INTERVENTION Participants were randomly assigned to one of 10 label formats classified into three groups: listing 2 servings per container with a single column, listing 2 servings per container with a dual column, and listing a single serving per container. Within these groups there were versions that enlarged the font size for "calories," removed "calories from fat," and changed the wording for serving size declaration. MAIN OUTCOME MEASURES The single product task measured product healthfulness, the amount of calories and various nutrients per serving and per container, and label perceptions. The product comparison task measured ability to identify the healthier product and the product with fewer calories per container and per serving. STATISTICAL ANALYSES PERFORMED Analysis of covariance models with Tukey-Kramer tests were used. Covariates included general label use, age, sex, level of education, and race/ethnicity. RESULTS Single-serving and dual-column formats performed better and scored higher on most outcome measures. CONCLUSIONS For products that contain 2 servings but are customarily consumed at a single eating occasion, using a single-serving or dual-column labeling approach may help consumers make healthier food choices.