Fatigue is a common and debilitating symptom among individuals with multiple sclerosis (MS). Researchers acknowledged the importance of addressing fatigue with low-risk interventions and focused on dietary approaches that offer potential advantages for multiple health parameters such as body mass index (BMI), insulin resistance, and lipid profile. Their primary objective was to assess the reduction in fatigue levels using the Modified Fatigue Impact Scale (MFIS) after a 14-week period. Secondary outcomes encompassed the evaluation of blood markers associated with inflammation, lipid metabolism, and gut microbiome composition. Clinical aspects such as cognitive function, mobility, and body composition were also examined.

Researchers conducted a two-arm, open-label, randomized controlled trial (RCT) to investigate the effects of a low-fat diet on individuals with multiple sclerosis (PwMS). Participants were divided into two groups: the low-fat diet group and the wait-list group. The diet group received one to two weeks of nutrition counseling and strict adherence to a low-fat diet for 12 weeks. The control group was offered the same nutrition counseling but after a delay of 14 weeks. Researchers utilized a monthly food frequency questionnaire and a 24-hour food recall method to assess adherence to the prescribed diet. They employed linear mixed effects modeling, incorporating a random effect for each participant, to analyze changes in average Modified Fatigue Impact Scale (MFIS) and Fatigue Severity Scale (FSS) scores within and between the two groups over time. As part of their sensitivity analysis, potential outliers from both groups were excluded to ensure accurate results.

The research involved 39 participants, with 20 assigned to the diet group and 19 to the control group. The mean age of the diet group was 52 years (± 10 years), while the control group had a mean age of 47 years (± 13 years). Both groups had a mean baseline body mass index (BMI) of 31 kg/m2 (± 7 kg/m2). The mean Expanded Disability Status Scale (EDSS) score was 4.2 (± 1.3) for the diet group and 3.4 (± 1.4) for the wait-list group. Throughout the 12-week RCT, participants in the diet group experienced a significant decrease in fatigue scores. The mean MFIS decreased by 4.00 (95% CI, –12.04 to 4.04), and the mean FSS decreased by 0.41 (95% CI, –1.18 to 0.36) from baseline to the end of the RCT, compared to the control group. Sensitivity analysis, which excluded five outliers, further strengthened the association, revealing a mean MFIS decrease of 13.93 (95% CI, –20.65 to –7.20) and a mean FSS decrease of 1.22 (95% CI, –1.94 to –0.50) in the diet group compared to the control group at the end of the RCT. The diet group exhibited a significant reduction in the percentage of calories from fat, assessed using a 24-hour food recall method. The decrease was 10.56% (95% CI, –18.50% to –2.97%) compared to the control group. Researchers are analyzing blood biomarkers and gut microbiome data to gain further insights into the intervention’s effects. 

The 12-week low-fat diet intervention led to a notable reduction in fatigue scores among individuals with MS compared to the control group. However, further studies with larger sample sizes and longer follow-up periods are required to validate and expand upon these findings.