Catabolic
A fasting tracker designed with restraint.
Catabolism is the metabolic state your body enters when it stops digesting and starts drawing on stored energy. It’s the quiet work that fasting is for. This app is named for it.
Catabolic is a fasting tracker designed with restraint. Inspired by mid-century industrial design — the tradition of Dieter Rams — it does one job and does it well: helping you keep a sustainable eating window.
The interface is quiet on purpose. A single timer. A visual hour ruler that fills as your fast progresses. A goal line you can actually see approaching. Nothing blinks, nags, or asks for your attention beyond what the moment requires.
Features
- Set a fasting goal from 12 to 24 hours
- Live timer with a visual hour ruler so you can see exactly where you are in your window
- Home screen widget — check your progress without opening the app
- Edit start time and goal mid-fast
- End-of-fast summary with the option to log notes
- Weekly average, last-fast time, and weekly trend at a glance
- Considered light and dark modes — typography and color tuned for both
Catabolic is focused on time-restricted eating (TRE) — the 12 to 16 hour window backed by current research. No accounts. No subscriptions. No social feed. No analytics, no ads, no third-party SDKs. Built entirely with Apple frameworks. Your fasting history stays on your device.
Support
Questions, bugs, or feedback? Email kyle@kylefiedler.com and I’ll get back to you.
Privacy
Privacy policy — the short version: nothing leaves your device.