The impact of time restricted eating on appetite and disordered eating in adults: A mixed methods systematic review

Abstract

This mixed-methods systematic review evaluated the effect of Time Restricted Eating (TRE) on adult participants' experience of hunger, appetite, and disordered eating. PubMed, CINAHL Plus with Full Text, PscyINFO, and Web of Science were searched for quantitative and qualitative original research articles in human adults that had an intervention with a daily eating window of ≤12 h and outcome measures related to hunger, appetite, or disordered eating. Differences in quantitative measures during TRE and qualitative themes were summarized. Qualitative and quantitative data were synthesized by assessing for convergence and divergence. Sixteen studies were included. TRE was associated with higher appetite at bedtime, and lower or unchanged morning fasting appetite. Evening results were mixed. Disordered eating questionnaires were not different as a result of TRE except in one study that found TRE associated with lower hunger. Qualitative themes converged with these findings, however also showed fear of hunger, eating in the absence of hunger, and eating-related stressors. TRE did not result in major changes to appetite or disordered eating symptoms. Bedtime hunger was higher in TRE. Assessment of subtle alterations in eating behavior, such as eating in the absence of hunger, would be beneficial for future research and intervention design.

Keywords: Appetite; Disordered eating; Eating behaviors; Fasting; Hunger; Time restricted eating.