Fiber enriched protein-free pasta and bread: Is it a useful tool in chronic kidney disease in type 2 diabetes?

BACKGROUND: Protein-free (PF) foods are routinely used in dietetic management of advanced chronic kidney disease in diabetic subjects. The enrichment by fiber has the purpose to reduce their impact on postprandial glucose levels. OBJECTIVE: Aim of this study was to determine the Glycemic Index (GI) of PF bread and pasta enriched with soluble psyllium and inulin fiber. METHODS: 14 adults, non obese, well controlled type 2 diabetic subjects consumed a 50 g carbohydrates containing serving of soluble fiber enriched PF pasta and PF bread. White bread was the reference food. Glucose levels were controlled fasting and at 30’, 60’, 90’, 120’ and 180’. RESULTS: PF bread induces a significantly higher glucose increase at 120’ and 180’ (p < 0.05) and PF pasta at 30’ vs white bread (p < 0.05); PF pasta induces significantly lower glucose levels at 90’ and 120(p < 0.05) after the meal. PF pasta had (a medium) GI (70,10 ± 22,6%), PF bread a high GI (117,32 ± 26,9%). CONCLUSIONS: These results confirm the unfavorable effect of PF food on postprandial glucose levels that is not limited by the addition of soluble fiber. In nutritional counselling it could be useful to suggest pasta to bread and include it in low GI meals.