(P24-09-26) Fiber for Improvement of Behavior, Eating, and Risk: Preliminary Results From a Randomized Trial

Objectives: Despite potential to improve health, fiber intake is resistant to standard intervention approaches focused on weight loss education. The objective of this study is to describe preliminary outcomes of a randomized trial comparing a fiber-focused intervention to standard weight loss education.

Methods: Adults with a body mass index ≥30 kg/m² were randomized to a 3-month fiber-focused intervention, Fiber for Improvement of Behavior, Eating, and Risk (FIBER), standard 12-month weight loss education using a wait-list design based on the Diabetes Prevention Program (WL), or a sequential combined approach (FIBER+WL). Outcomes were assessed at baseline, post-FIBER (3 months), after WL (15 months), and one year later (27 months). Diet (and fiber intake) was assessed via 3-day diet records. Body weight and blood pressure were assessed at baseline, 15 months, and 27 months. Self-reported initiation of glucagon-like peptide-1 receptor agonists (GLP-1 RA) was assessed. Fiber intake at 3 months was compared across those who received FIBER or FIBER+WL to WL only using Wilcoxon Rank-Sum tests. Weight and blood pressure were analyzed using one-way analysis of variance.

Results: A total of n=69 adults were randomized. At 3 months, fiber intake was significantly higher in those in FIBER or FIBER+WL compared to WL (23.04 ± 8.54 g/day versus 15.41 ± 5.40 g/day [P=0.01]). In total, 11.11% of FIBER, 20% of FIBER+WL, and 50% of WL participants started using a GLP-1 RA (P=0.06). No significant differences were seen in blood pressure across groups, though medium effect sizes were seen for diastolic blood pressure at 27 months (ƞ²=0.07), which was lowest in FIBER (80.22 ± 6.88 mmHg) and highest in FIBER+WL (85.55 ± 10.65 mmHg). When excluding those on GLP-1 RAs, this effect increased (ƞ²=0.19) and was lowest in FIBER (79.62 ± 6.72 mmHg) and highest in WL (89.33 ± 9.53 mmHg). No significant differences in percent weight change were seen at 27 months; when excluding participants on GLP-1 RAs, percent weight loss was -0.7% in FIBER, -3.7% in FIBER+WL, and -0.51% in WL.

Conclusions: Promoting fiber intake within standard weight loss advice may lead to long-term benefits on cardiometabolic health and weight maintenance over time.

Funding Sources: Hudson College of Public Health, Oklahoma Center for the Advancement of Science and Technology, Oklahoma State University, Tobacco Settlement Endowment Trust