Abstract
The glycemic index (GI) reflects the postprandial glucose response of carbohydrate-containing foods, and adoption of a lower-GI diet may be beneficial in diabetes management. The purpose of this study was to evaluate change in food-group intake by participants after completing an intervention that included instruction about carbohydrate and the GI using a quasi-experimental design. Recruitment occurred from February to August 2005 and September to December 2006. Individuals 40 to 70 years old with type 2 diabetes for 1 year or longer were randomly assigned to an immediate (n=55) or delayed (n=48) treatment group. A 9-week group-based intervention regarding the quantity and type of carbohydrate for diabetes management was provided. Three sets of 24-hour dietary recalls were used to assess food-group intake. Foods were divided into nine main food groups and 166 subgroups based on the Dietary Guidelines for Americans 2005 and the United States Department of Agriculture's Food Guide Pyramid. Analysis of variance was used to examine between-group differences and paired t test compared maintenance of change for the immediate group. Change in dietary GI was significantly different between groups upon completion of the intervention by the immediate group (P<0.05). Participants consumed significantly more servings of whole fruit and nonfat dairy products following the intervention and fewer servings of vegetable fats (all P<0.05). Only whole-fruit consumption significantly declined in the immediate group during the maintenance period (P<0.05). Nutrition education can facilitate adoption of a lower-GI diet among free-living people with diabetes. Maintaining dietary change likely requires further intervention and support.