obesity, protein diet, dietary interventions


Obesity affects adults in the United States, leading to chronic diseases and reduced well-being. Time-Restricted Feeding (TRF) is a type of dietary intervention lacking current data regarding the effectiveness on facets of well-being. This study’s objective was to determine the effect of time-restricted feeding supplemented with whey protein isolate on food intake, sleep, and mood in overweight or obese adults. Nineteen participants were randomly assigned to the control or experimental group: 1) control, TRF, and 2) experimental, TRF with whey protein supplementation. Participants followed the assigned dietary intervention for 12 weeks. Every 4 weeks (baseline, week 4, week 8, and week 12), anthropometrics, including height and weight, were measured along with the Pittsburg Sleep Quality Index (PSQI) questionnaire, Profile of Mood States (POMS) questionnaire, and dietary record results. Additionally, ActiGraphy measured objective sleep quality at week 1 and week 12. There were no differences between the control and protein groups regarding sleep and mood parameters. The PSQI results indicated no difference in sleep between groups. The POMS subscores for tension-anxiety, when controlled for baseline, were different, with a decrease in the protein group compared to the control at week 12 (P < 0.01). Total food consumption was similar between groups. The results suggested whey protein isolate supplementation with TRF may improve outcomes of mood with no effect on sleep. Therefore, a need for further research to investigate the benefits of TRF and protein supplementation on sleep and mood is necessary.