16:8 fasting works. No better than 3 meals.

People say: “Skip breakfast and the fat melts off” We read the study.

What they did

Randomised controlled trial (RCT). 141 people. 12 weeks.

A trial. Chance decided who did what.

Who: US adults aged 18-64 with BMI 27-43 (overweight/obesity) who regularly ate breakfast; no diabetes; 116 analysed (70 [60.3%] men, mean age 46.5, mean weight 99.2 kg); in-person subset of 50 near San Francisco

What they found
  • 16:8 vs 3 meals-0.26 kg
  • Both groups< 1 kg
  • Arm & leg lean mass-0.47 kg
The catch

More to know, from our read of the paper:

  • Only 12 weeks
  • 141 randomized but 25 never sent any data; 116 analysed, 105 completed
  • Calorie and protein intake were not measured (energy intake was estimated by mathematical modelling)
  • Adherence was self-reported via a daily yes/no app survey
  • Body composition and metabolic tests only in the in-person subset (n=50; 46 completers)
The verdict

No better than meals. May cost lean mass.

One thing to try
  1. Timing alone isn't a planOnly timing changed. Weight barely did.
  2. Like 16:8? Keep itNo worse for blood sugar or cholesterol.
  3. Watch your lean massFasters lost more in arms and legs.
In short

141 adults with overweight were randomly split: eat only between 12 and 8 PM, or eat 3 meals a day, for 12 weeks. No calorie rules. The 16:8 group lost just 0.26 kg more, which wasn't a real difference. In a smaller lab group, they lost more arm and leg lean mass. Blood sugar and cholesterol didn't differ.

The paper

Lowe et al. (2020). Effects of Time-Restricted Eating on Weight Loss and Other Metabolic Parameters in Women and Men With Overweight and Obesity: The TREAT Randomized Clinical Trial. JAMA Internal Medicine.

Design: Randomised controlled trial (RCT) · randomized controlled trial

DOI: 10.1001/jamainternmed.2020.4153

Goals:

Eat better
How we checked

We read the abstract and the full text of this paper and checked every number on this page against it (16 facts, checked on 2026-09-26). The study design is named above. Cohort and other observational studies are described as linked, not proven. Found an error? Email theis@onestudyaday.com.

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