Abstract
BACKGROUND: Youth with type 1 diabetes do not count carbohydrates accurately, yet it is an important strategy in blood glucose control. OBJECTIVE: The study objective was to determine whether a nutrition education intervention would improve carbohydrate counting accuracy and glycemic control. DESIGN: We conducted a randomized, controlled nutrition intervention trial that was recruited from February 2009 to February 2010. SUBJECTS: Youth (12 to 18 years of age, n = 101) with type 1 diabetes were screened to identify those with poor carbohydrate counting accuracy, using a previously developed carbohydrate counting accuracy test covering commonly consumed foods and beverage items presented in six mixed meals and two snacks. All participants (n = 66, age = 15 ± 3 years, 41 male, diabetes duration = 6 ± 4 years, hemoglobin A1c [HbA1c] = 8.3% ± 1.1%) were randomized to the control or intervention group at the baseline visit. The intervention group attended a 90-minute class with a registered dietitian/certified diabetes educator and twice kept 3-day food records, which were used to review carbohydrate counting progress. MAIN OUTCOME MEASURES: Carbohydrate counting accuracy (measured as described) and HbA1c were evaluated at baseline and 3 months to determine the effectiveness of the intervention. STATISTICAL ANALYSES PERFORMED: t Tests, Spearman correlations, and repeated measures models were used. RESULTS: At baseline, carbohydrate content was over- and underestimated in 16 and 5 of 29 food items, respectively. When foods were presented as mixed meals, participants either significantly over- or underestimated 10 of the 9 meals and 4 snacks. After 3 months of follow-up, HbA1c decreased in both the intervention and control groups by -0.19% ± 0.12% (P = 0.12) and -0.08% ± 0.11% (P = 0.51), respectively; however, the overall intervention effect was not statistically significant for change in HbA1c or carbohydrate counting accuracy. CONCLUSIONS: More intensive intervention might be required to improve adolescents' carbohydrate counting accuracy and nutrition management of type 1 diabetes. Additional research is needed to translate nutrition education into improved health outcomes.