Glycemic index of some protein-free food products for individuals with non-dialysis-dependent chronic kidney disease

Background: Chronic kidney disease (CKD) is a major public health issue and the third leading cause of death globally. In the conservative phase of CKD, a low-protein diet is recommended to slow disease progression, and protein-free products are commonly used in clinical nutrition for CKD. Since diabetes is highly prevalent in this population, it is crucial that such foods also have a low glycemic index (GI) to support glycemic control and reduce associated complications. This study aimed to assess the GI of selected commercial protein-free products. Methods: Twelve healthy volunteers (six males, six females; mean age 20.7 ± 0.8 years; BMI 22.6 ± 3.6 kg/m²) consumed four commonly available protein-free foods: sliced white bread, pasta, crackers, and cookies filled with vanilla cream (with sweeteners). The GI of each product was calculated according to ISO 2010 standards, using glucose as a reference. Each test meal provided 50 g of available carbohydrates. Results: GI values ranged from 48 for cookies filled with vanilla cream to 69 for crackers. Sliced white bread (GI 49.4) and cookies (GI 47.8) were classified as low-GI foods, while pasta (GI 68.2) and crackers (GI 69.2) fell within the medium-GI range. Conclusion: Several commercially available protein-free products exhibit low to moderate GI values, supporting their use in dietary management of patients with non-dialysis-dependent CKD and or at risk of diabetes. However, given the growing market of such products, further studies—including those on patients with CKD—are needed to expand the current evidence base.