Irregular feeding patterns have adverse effects on a variety of physiological and metabolic processes, independent of meal size and composition. Meal timing has a marked effect on health and can be manipulated to prevent and treat obesity as well as other metabolic disorders, especially in rodent models. Hunger and mood may influence dietary adherence and therefore the effects of dietary changes on psychological health should be considered. We tested the effects of time-restricted feeding (TRF) on measures of mood, hunger and fatigue.
Eleven sedentary males (age 38 ± 5 y; BMI: 32.1 ± 2.1 kg/m2) completed two 5-day isoenergetic diet protocols in a randomised order, consuming three meals between 10:00 - 17:00 h (TRF; 8 h eating window) or between 07:00 - 21:00 h (unrestricted feeding, URF; 15 h). On the 5th day, participants attended the laboratory for 24 h and completed visual analogue scales hourly (07:00-22:00 h and 07:00 h) for hunger and fatigue and at four hourly intervals from 08:00 h for positive and negative mood states (Positive And Negative Affect Scale).
Ratings of hunger were altered across time (P<0.001) and between conditions (interaction effect, P<0.001), relative to the timing of meals. No differences in hunger between the conditions were found at 07:00 h on the fifth day or 24 h later. Ratings of fatigue increased across the day (P<0.001) but not differently between conditions. Neither positive nor negative affect mood scores were changed by TRF. However, a main effect of order was observed, with increased negative affect scores in the second condition (P=0.027); which may be due to the high study demands.
Short-term TRF had little effect on ratings of hunger, fatigue or mood states. TRF is a practical dietary approach and adherence to TRF over longer time periods may alter these psychological health and well-being factors.