Background : Fatigue is a common symptom of multiple sclerosis (MS) and impacts quality of life, yet the role of chrononutrition and sleep in MS management remains underexplored. We aimed to investigate the cross-sectional associations of meal and sleep timing with fatigue in persons with MS (pwMS).

Methods : We implemented a chrononutrition questionnaire within the Swiss MS Registry to quantify the relationships between meal timing, sleep patterns and fatigue among pwMS.

Results : In unadjusted analyses of 958 participants (median age 49 years, 73% women), a longer interval between the first and last meals (eating window) was associated with less fatigue (OR per 1 SD change in predictor=0.84, 95% CI 0.75 to 0.94), while later wake-up (OR 1.26, 95% CI 1.12 to 1.43) and first meal (OR 1.28, 95% CI 1.14 to 1.44) were associated with more fatigue. Later weekend versus weekday patterns (‘social jetlag’) across meal and sleep timing were associated with less fatigue.

Adjustment for lifestyle factors attenuated most of the relationships, with employment status being the most influential. After adjustment, a larger ‘social jetlag’ in first meal (OR 0.86, 95% CI 0.76 to 0.97) and going to bed later (OR 0.86, 95% CI 0.76 to 0.97) remained associated with less fatigue, while a longer time in bed (OR 1.28, 95% CI 1.12 to 1.46) remained associated with more fatigue.

Conclusions : Associations of meal and sleep timing with fatigue in pwMS were influenced by lifestyle factors, particularly employment status. After adjustment, eating the first meal later during weekends compared with weekdays, going to bed later and a shorter time in bed were associated with less reported fatigue. The apparent benefits of ‘social jetlag’ on first meal times require confirmation from prospective and interventional studies.