A low-fat diet improves fatigue in multiple sclerosis: Results from a randomized controlled trial

Background: Fatigue can be a disabling multiple sclerosis (MS) symptom with no effective treatment options. Objective: Determine whether a low-fat diet improves fatigue in people with MS (PwMS). Methods: We conducted a 16-week randomized controlled trial (RCT) and allocated PwMS to a low-fat diet (active, total daily fat calories not exceeding 20%) or wait-list (control) group. Subjects underwent 2 weeks of baseline diet data collection (24-hour diet recalls (24HDRs)), followed by randomization. The active group received 2 weeks of nutrition counseling and underwent a 12-week low-fat diet intervention. One set of three 24HDRs at baseline and week 16 were collected. We administered a food frequency questionnaire (FFQ) and Modified Fatigue Impact Scale (MFIS) every 4 weeks. The control group continued their pre-study diet and received diet training during the study completion. Results: We recruited 39 PwMS (20—active; 19—control). The active group decreased their daily caloric intake by 11% (95% confidence interval (CI): −18.5%, −3.0%) and the mean MFIS by 4.0 (95% CI: −12.0, 4.0) compared to the control (intent-to-treat). Sensitivity analysis strengthened the association with a mean MFIS difference of −13.9 (95% CI: −20.7, −7.2). Conclusions: We demonstrated a significant reduction in fatigue with a low-fat dietary intervention in PwMS.