# Phone breathalyser detects when body starts burning fat

A phone-connected device measures acetone levels in breath to indicate when the body enters ketosis and begins burning fat for energy. This non-invasive tool helps people track their metabolic state for diet or exercise optimization. It offers a convenient way to monitor fat-burning without blood tests.

**Importance:** 2/5

## Sources

### Science
- [New Scientist](https://www.newscientist.com/article/2580739-breathalyser-detects-when-your-body-is-burning-fat/?utm_campaign=RSS|NSNS&utm_content=home&utm_medium=RSS&utm_source=NSNS) — Wed, 22 Jul 2026 15:00:00 +0000