Usual Dietary Fiber Intake According to Diabetes Status in US Adults: NHANES 2013-2018.

It is unknown if fiber intake differs across diabetes status in US adults and is associated with glycemic outcomes. This retrospective analysis utilized National Health and Nutrition Examination Survey (NHANES) cycles 2013 - 2018 data to estimate usual total dietary fiber intake in US adults and across diabetes status (no diabetes, prediabetes, type II diabetes (T2D)). Associations among dietary fiber intake and glycemic outcomes were also reported across groups. Adults (≥19 y) with at least one dietary recall were included. Diabetes status was determined from self-report data and measured hemoglobin A1c. Independent samples t-tests were used to compare mean (SE) intake across sub-populations. 14,640 adults (51.3% female) with 26.4% and 17.4% classified as having prediabetes and T2D, respectively. Adults with T2D reported greater mean (SE) dietary fiber intake compared to no T2D for females (9.5 (0.13) vs 8.7 (0.11) g/1,000 kcal/d and males (8.5 (0.12) vs 7.7 (0.11) g/1,000 kcal/d; P < 0.01)). However, only 4.2 (0.50)% and 8.1 (0.90)% of males and females with T2D, respectively, met the adequate intake for fiber. Fiber intake was associated with lower insulin (β = -0.80, P <0.01), serum glucose (β = -1.35, P <0.01), and HOMA-IR (β = -0.22, P <0.01) in adults without diabetes and no relationships in adults with prediabetes or T2D were found. Although dietary fiber intake was highest among adults with T2D, intake was suboptimal across all groups. In adults without diabetes dietary fiber intake was associated with improved glycemic outcomes and insulin resistance.