Talk to a doctor first if
| If this applies | Why |
|---|---|
| You are pregnant or breastfeeding | Steady nutrition matters for both parent and baby |
| You are under 18 | Restricting eating time is not recommended while growing |
| You take insulin or other glucose-lowering drugs | Long fasts can raise the risk of low blood sugar |
| You have or had an eating disorder | Time rules can bring back restrictive or obsessive eating |
| You have heart or kidney disease, are underweight, or take regular medication | Medication timing may clash with fasting |
| You are older and recently lost weight or muscle | A shorter window can make low protein intake worse |
Johns Hopkins Medicine also advises children and teens under 18, people who are pregnant or breastfeeding, people with type 1 diabetes who take insulin, and people with a history of eating disorders to avoid intermittent fasting. The app’s store listing carries a similar medical disclaimer.
Signs to stop a fast
- Dizziness, cold sweats, shakiness, a racing heart
- Fatigue that stops you concentrating, or a persistent headache
- Drowsiness while driving or operating machinery
- Changes to your menstrual cycle or worse sleep lasting weeks
If symptoms are severe or keep returning, stop and see a doctor. "Push through and you will adapt" does not apply to every symptom.
When tracking turns into pressure
Timers and streaks are motivation tools. But if you feel anxious about breaking a streak, only feel at ease when fasts get longer, or keep bingeing inside the window, the tool is doing harm. That is the time to put the app down and talk to a professional.
Using the app safely
The timer keeps counting past the goal
When the goal passes, the screen switches to "Goal reached" and the "Over goal" time keeps rising. There is no goal notification, so once you are past it, do not wait; tap "Stop Fasting" and eat.
Be careful with long presets
The app includes a 24h preset, but it is not suitable for beginners or anyone on the list above. For a gentler start see 16:8 vs 14:10.
FAQ
I have type 2 diabetes but take no medication. Is fasting okay?
Even without medication, it is safer to plan blood sugar management with your doctor. Mention your fasting plan at your next visit.
My parents want to try intermittent fasting. Any concerns?
For older adults, muscle loss and medication timing are the main concerns. Encourage them to check with their doctor first.
Sources: Johns Hopkins Medicine, Intermittent Fasting
Intermittent Fasting Timer: 16:8 Diet & Fasting Log
No sign-up, works offline, and your fasting log stays on your phone. Free on Android, in English and Korean.