# Intermittent Fasting: 5:2 Melted Fat Faster Than 16:8

_Evidence Level: Moderate · Kim H et al., Obesity (Silver Spring, Md.), DOI 10.1002/oby.70322_

*Daily 16:8 Versus Weekly 5:2 Intermittent Fasting for Weight Loss and Metabolic Health: A Randomized Controlled Trial.*

- **Evidence Level**: Moderate
- **Why this grade**: Researchers randomly split 68 women between two fasting plans, but the trial lasted only four weeks, was open-label and had no non-fasting group.
- **Facts**: Design: Randomized controlled trial · Duration: 4 weeks · Funding: National Research Foundation of Korea
- **Publication Types**: Journal Article
- **Journal**: Obesity (Silver Spring, Md.)
- **Sample Size**: 68 women with overweight or obesity
- **Authors**: Kim H, Yun W, Han J, Song Y
- **Graded and published**: 2026-10-28
- **Last edited**: 2026-10-30
- **Topics**: Fasting, Metabolic Health
- **DOI**: https://doi.org/10.1002/oby.70322
- **Original Source**: https://pubmed.ncbi.nlm.nih.gov/42950885/

## Summary

Two popular styles of intermittent fasting worked out similarly well in a head-to-head test. Women with excess weight lost 2.7 kilos on average over four weeks, and 1.7 kilos of that was fat. Over time, though, weight and fat dropped further in the 5:2 group than in the 16:8 group.

The trial included 68 women with overweight or obesity, assigned at random to one plan. One group ate only within an eight-hour window each day and fasted for 16 hours. The other ate normally five days a week. On two days, they had a very low-calorie diet designed to mimic fasting. Both groups ate less and over shorter stretches of the day. Waist size and blood pressure fell, and average and peak blood sugar went down. The women also lost about 0.6 kilos of muscle mass, a similar amount in both groups.

The study cannot say whether one plan wins in the long run. It lasted only four weeks, and everyone knew which plan they followed. There was no group that did not fast, and only women took part.

## Practical Takeaway

Women lost weight on both fasting plans in four weeks, but weight and fat fell further over time with 5:2 than with 16:8.

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_Canonical: https://longevity-cities.com/en/research/intermittent-fasting-5-2-melted-fat-faster-than-16-8 · Part of Longevity Cities · Updated 2026-10-30_