Glycemic index, glycemic load and dietary fiber of foods and its association with insulin resistance in Chilean adults

Glycemic index and glycemic load (GI and GL) categorize foods according to their ability to increase blood sugar levels, considering quantity and quality of carbohydrates consumed. Different studies have postulated that a high GI and GL diet and low fiber intake increased glycemia and insulinemia, although with heterogeneous results. The aim of this study was to analyze the association between GI, GL and fiber intake and HOMA-IR values in young adults. In a representative sample of 738 people aged between 32 and 38 years old, born in the Limache's Hospital, Valparaiso, Chile, socioeconomic and health information, nutritional status, basal glycemia, insulin and HOMA were collected. With a food frequency questionnaire, GI, GL and fiber intake were estimated. Multiple regression models were constructed, controlling confounding and interaction effects. In adjusted models, it was found that for every 10 units that increases diet GI and GL in overweight individuals, HOMA-IR increases in 0.31 (p = 0.042) and 0.03 (p = 0.012) respectively, and for every 10 grams that increases total and soluble fiber intake, HOMA-IR reduces in 0.10 (p = 0.04) and 0.62 (p = 0.034) respectively. In people without overweight such effects were not observed. There was a direct association between increased GI and GL foods and increased HOMA-IR only in individuals with overweight and an inverse association between total and soluble fiber intake and HOMA-IR.