Research

Hormonal

A time-restricted eating protocol with a 16-hour fasting window (16:8) significantly reduces body mass and absolute fat mass in metabolically healthy, non-trained individuals, whereas 12-hour and 14-hour fasting windows do not produce significant changes.

If you are healthy and not trying to build muscle, try eating all your meals within an 8-hour window (e.g., 10am to 6pm) and fasting for the other 16 hours daily for 8 weeks. Do not try to restrict calories; just stick to the timing. You may lose fat mass without changing how much you eat, but 12-hour or 14-hour windows likely won't work for you.

ModerateQualifiesMEDIUM confidence
Our results suggest that a 16-hour fasting window, even without caloric restriction, may be a viable strategy for improving body composition in healthy and non-trained individuals, whereas a shorter fasting period may be insufficient to produce significant changes in a healthy population.
Alicia Sampieri et al. · Journal of Translational Medicine · 2024

Why this rating

Randomized controlled trial with a small sample size (n=41) and short duration (8 weeks), conducted in a specific, healthy, non-trained population.

Source

Impact of daily fasting duration on body composition and cardiometabolic risk factors during a time-restricted eating protocol: a randomized controlled trial

Alicia Sampieri et al. · Journal of Translational Medicine · 2024

DOI 10.1186/s12967-024-05849-6

rct · n=41Cited 14×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →