BACKGROUND/OBJECTIVES: The effects of sweetened and unsweetened high β-glucan whole grain barley on postprandial blood glucose response in normoglycemic human subjects were evaluated in a randomized, controlled, crossover clinical trial. METHODS: Sixteen healthy, over-night fasted participants were studied on four or eight separate occasions. Participants consumed an unsweetened preload condition ( RESULTS: In both sweetened and unsweetened conditions, higher β-glucan content was associated with lower blood glucose peak response and incremental area under the curve estimates (iAUC). In comparison to the unsweetened conditions, the sweetened conditions resulted in less prominent decreases in mean blood glucose response and iAUC blood glucose as β-glucan content increased. CONCLUSIONS: By attenuating postprandial glycemic response, high β-glucan whole grain barley foods could play a role in helping to control blood glucose.