A Smartphone App Reveals Erratic Diurnal Eating Patterns in Humans that Can Be Modulated for Health Benefits.
Level 4 - case-series / case-control
Prospective single-arm before-after intervention and observational tracking without a control group.
PubMed 26411343 · doi:10.1016/j.cmet.2015.09.005
What was done
Healthy non-shift-working adults logged food and beverage ingestion events using a smartphone app over several days to characterize diurnal eating patterns. A subgroup of overweight individuals with daily eating durations exceeding 14 hours was then placed on a 16-week time-restricted eating intervention limiting daily intake to a 10- to 11-hour window, aided by an intake visualization tool ("feedogram"), with follow-up extending to one year.
What was found
Eating was frequent and erratic throughout waking hours, with overnight fasting duration closely mirroring time spent in bed. Calorie intake was skewed late: an estimated <25% of calories were eaten before noon and >35% after 6 p.m., with frequent weekday-to-weekend timing shifts ("metabolic jetlag"). For half the cohort, the daily intake duration (95% interval) exceeded 14.75 hours. Reducing the eating window to 10–11 hours daily for 16 weeks in overweight individuals led to body weight reduction, improved self-reported sleep, and increased energy, with benefits lasting one year. The abstract reports no sample sizes or numerical effect sizes for weight loss or sleep.
Why it matters
This study provided early real-world evidence of prolonged daily eating windows in humans and demonstrated that time-restricted eating without explicit calorie counting can achieve sustained weight loss.
Limits
The abstract omits sample sizes (n), demographic details, and exact numerical changes for body weight and sleep metrics. The intervention was an uncontrolled, single-arm trial, making it impossible to rule out placebo effects, self-monitoring bias, or concurrent spontaneous caloric restriction.
Cited by
- supports App data from the myCircadianClock study shows that nearly 50% of adults have a daily eating window of 15 hours or longer, while only 10% eat within a 12-hour or shorter window.
- supports In a study of 156 people, fewer than 5% self-reported on a questionnaire that their daily eating window exceeded 13 hours.
- supports Only 10% of adults consume all their daily calories within a 12-hour or shorter window.