BACKGROUND: Time-restricted eating (TRE) and intermittent fasting (IF) are emerging nutritional strategies with potential benefits for metabolic and clinical health. However, the variety of fasting models and overlapping mechanisms and behaviors has led to conceptual ambiguity. This scoping review synthesizes recent evidence on TRE regarding metabolic regulation, glycemic control, appetite, gut microbiota, circadian alignment, and cancer support.
METHODS: A comprehensive search was conducted in PubMed, Web of Science, CrossRef, and Google Scholar. Included studies were randomized or non-randomized trials and observational studies focused on TRE, excluding alternate-day and prolonged fasting. Data were thematically charted and descriptively synthesized across metabolic and hormonal outcomes, gut microbiota, chrononutrition, and oncology.
RESULTS: Eighty-one studies met the inclusion criteria. TRE protocols (e.g., 16:8, 14:10) improved body composition, insulin sensitivity, lipid profiles, and inflammation. Evidence also points to enhanced mitochondrial function, appetite hormone modulation, and gut microbiota diversity. Early feeding aligned with circadian rhythms yielded better glycemic outcomes. Although several benefits can occur independently of a negative energy balance, in real-world practical settings, TER may coincide with unintentional reductions in energy intake and other lifestyle adjustments. Therefore, these effects underscore the need for careful monitoring to safeguard nutritional adequacy and support long-term sustainability. Preliminary findings also suggest potential adjunctive roles in cancer care.
CONCLUSIONS: TRE represents safe, adaptable, and clinically relevant strategies for metabolic health when individualized and professionally supervised. While mechanistic and clinical data are encouraging, long-term adherence and sustainability remain key research priorities.
