The Effect of Protein Supplementation During Time Restricted Feeding in Overweight and Obese Adults

Obesity in the United States continues to increase. Time restricted feeding (TRF) is a dietary intervention that has potential to serve as an effective weight loss strategy, however more data is needed to establish the effectiveness of a TRF eating pattern on health outcomes related to obesity. To our knowledge, manipulation of macronutrient distribution during a TRF intervention and the effect of TRF on sleep and mood have not been studied. Therefore, the objective of this study was to determine the effect of protein supplementation during TRF on mood, sleep, and appetite in overweight and obese adults.Overweight and obese men and women (36.6±7.3 years; BMI: 32.8±6.5) participated in this randomized, controlled 12-week dietary intervention. Participants were allocated to one of two groups: 1) control, TRF (n=7) and 2) TRF with whey protein supplementation (25 g/d; n=9). Protein supplements were consumed at the breaking of the fasting period each day. Anthropometrics, sleep (via Pittsburgh Sleep Quality Index Global Sleeping Score; PSQI GSS), total mood disturbances (TMD; via Profile of Mood States (POMS) including six affect states of depression, fatigue, anger, tension, confusion, and vigor subscales), and appetite (using visual analog scales) were assessed at 0, 4, 8, and 12 weeks. Sleep was also measured at 0 and 12 weeks via wrist Actigraphy. Body composition was measured via DXA at 0 and 12 weeks. Data was analyzed using two-way ANOVA to assess the relationship.Overall, both interventions improved total body fat percentage (p<0.05) over 12 weeks. There was a significant difference in mood between intervention groups (p<0.001) and the control group total mood disturbance was significantly different (p<0.05) between week 1 and 12. However, there was no change in mood with protein supplementation over the span of 12 weeks. Sleep, self-reported via PSQI, did not change from week 1 and week 12 within or between each of the interventions. Appetite did not show a significant difference between interventions or time points.This pilot study suggests that protein supplementation during TRF has the potential to improve body composition in overweight and obese individuals. However, additional research is needed to determine the long-term effect of protein supplementation in combination with TRF on mood, sleep, and appetite.