Study of How High-Fat and Low-Fat Diets Affect the Human Bodys Daily Biological Clock

What this Trial Is About

Researchers are investigating how diet affects the human circadian timing system, which is essential for regulating biological processes and overall health in sync with the 24-hour light-dark cycle. This study focuses on how quickly the bodys internal clock adjusts or entrains when exposed to a high-fat diet, based on evidence from animal studies showing that high-fat diets can disrupt circadian rhythms. The trial aims to better understand these effects in healthy adults aged 18 to 40. The study uses a 46-day randomized crossover design with two diet interventions a high-fat diet 50% fat, 35% carbohydrates, 15% protein and a low-fat diet 30% fat, 55% carbohydrates, 15% protein. Participants will complete two inpatient visits of nine days each, separated by outpatient periods. During outpatient phases, they will follow strict sleep schedules and consume provided meals. In the inpatient phase, participants stay in controlled rooms without time cues while undergoing detailed monitoring including sleep studies, body temperature measurements, blood sampling, and metabolic assessments. Participants will maintain consistent sleep schedules verified by sleep logs and actigraphy before each inpatient visit. Researchers will monitor circadian phase changes, metabolic health markers, cognitive function, and mood over 18 days of diet exposure. The study includes 24-hour supervision by medical staff and continuous data collection to assess how diet influences circadian entrainment speed and related physiological outcomes. Total participation spans approximately 46 days with detailed health and behavior assessments throughout.

Food and Circadian Timing