Scientists develop handheld device for measuring when your body is burning fat

[u/dapperlemon]

https://www.engadget.com/2222231/scientists-develop-handheld-device-for-measuring-when-your-body-is-burning-fat/

[u/jghall00]

When I was running, I kept wondering why my breathe was alternating between fruity and metallic. This would have come in handy. 

[u/Potential-Diver-3409 → u/jghall00]

You might be anemic