Glycemic index (GI) represents the postprandial glucose response of carbohydrate foods, and glycemic load (GL) represents the quantity and quality of carbohydrate consumed. A diet lower in GI and GL may improve diabetes management. A 9-week intervention regarding GI and GL was evaluated among adults in the age range of 40-70 years who had had type 2 diabetes ≥1 year (n = 103). Randomized pre—post test design with immediate and delayed treatment groups was employed. Dietary intake, knowledge, outcome expectations, self-efficacy, and empowerment regarding GI and GL and glucose monitoring were assessed. Four components were identified for outcome expectations using principal components analysis (dietary barrier, glycemic control, family support, and glucose monitoring), and two components were identified for self-efficacy (GI and self-regulation). Significant improvements in GI, knowledge, empowerment, self-efficacy, and outcome expectations (all p < .05) were observed except for glucose monitoring expectations. Only self-regulation efficacy significantly declined (p < .05) at the follow-up assessment in the immediate group. Nutrition education regarding GI and GL can improve dietary intake, knowledge, outcome and efficacy expectations, and empowerment for diabetes management.