Intermittent fasting for a lighter body and a sharper mind

Lose weight, boost your energy and think clearer with intermittent fasting. Get a personalized 16:8 plan, a smart fasting timer and progress tracking, whether you are just starting or already experienced.

Takes 2 minutes · Personalized plan · Science-based

What Is Intermittent Fasting?

Intermittent fasting (IF) is a time-restricted eating pattern that alternates between periods of fasting and eating. Rather than restricting what you eat, IF focuses on when you eat. During fasting periods, the body shifts from using glucose for energy to burning stored fat, a metabolic state known as ketosis. This process triggers autophagy - the body's cellular cleanup mechanism - which removes damaged cells and promotes regeneration. Its effects reach beyond weight: studies associate intermittent fasting with steadier energy, sharper focus and better metabolic health, which is why more people are asking what fasting does to both the body and the brain.

Research published in the journal Nutrients shows that intermittent fasting improves metabolic health markers including insulin sensitivity, blood pressure, and cholesterol levels (Li et al., 2023). The most popular methods include 16:8 (16 hours fasting, 8 hours eating), 18:6, and 5:2 (eating normally 5 days, restricting calories 2 days).

FastTrack is an iOS app that helps you practice intermittent fasting safely and effectively with a smart timer, progress analytics, and customizable fasting plans. All health data is stored locally on your device for complete privacy.

Everything You Need to Succeed

Smart Fasting Timer

Start, pause, and track your fasts with precision. Receive notifications when your fasting window ends and get ready to break your fast mindfully.

Progress Analytics

Visualize your fasting streaks, weight trends, and health improvements. Watch your body transform with detailed charts and insights.

Custom Fasting Plans

Choose from popular fasting methods like 16:8, 18:6, or create your own schedule. FastTrack adapts to your lifestyle and goals.

Why Choose FastTrack?

Reach Your Weight Goal

A fasting plan built around your goal and your routine. No restrictive diet, no yo-yo effect, a rhythm you can actually keep.

Steadier Energy All Day

Fewer crashes after meals. A consistent fasting window helps your energy stay level from morning to night.

A Clearer, Sharper Mind

Many fasters notice better focus during their fast. Research associates intermittent fasting with mental clarity and brain health.

Privacy First

Your health data stays on your device. We never share or sell your information. Complete privacy guaranteed.

Frequently Asked Questions

What is intermittent fasting and how does it work? +
Intermittent fasting is an eating pattern that cycles between periods of fasting and eating. It doesn't specify which foods to eat, but rather when you should eat them. Popular methods include 16:8 (fasting for 16 hours, eating within 8 hours) and 18:6. FastTrack helps you track these windows effortlessly.
Is FastTrack suitable for beginners? +
Absolutely! FastTrack is designed for everyone, from complete beginners to experienced fasters. We provide guided fasting plans, educational content, and gentle reminders to help you start your journey safely and effectively.
Can I customize my fasting schedule? +
Yes! While we offer popular preset schedules like 16:8 and 18:6, you can create completely custom fasting windows that fit your lifestyle. Adjust your schedule anytime to match your needs.
Is my health data private and secure? +
Your privacy is our top priority. All your health data is stored locally on your device and synced securely via iCloud. We never sell or share your personal information with third parties.
What can I drink while fasting? +
During your fasting window, you can drink water, black coffee, plain green tea, black tea, and herbal tea. Avoid adding sugar, milk, cream, or artificial sweeteners, as these can break your fast by triggering an insulin response. See our full guide to what breaks a fast.
How much weight can I lose with intermittent fasting? +
Most people lose 2-10 pounds in their first week of intermittent fasting, though much of this is water weight. Sustainable fat loss typically ranges from 1-2 pounds per week. Results vary based on your fasting method, diet quality, activity level, and starting weight. FastTrack helps you track your progress over time for realistic expectations.
Is intermittent fasting safe for women? +
Yes, intermittent fasting can be safe and beneficial for women when practiced correctly. Women may benefit from starting with shorter fasting windows (14:10) and gradually increasing. Some women prefer crescendo fasting (fasting 2-3 non-consecutive days per week). Fasting is not recommended during pregnancy, breastfeeding, or for those with eating disorders. Always consult a healthcare provider first.
When does ketosis start during fasting? +
Your body typically begins entering ketosis between 12-24 hours of fasting, depending on factors like your activity level, diet, and metabolism. By 24-48 hours, most people are in full ketosis, where the body primarily burns fat for fuel. FastTrack shows you which metabolic stage you're in during your fast.
Does intermittent fasting cause muscle loss? +
Not if you do it well. Keep your protein intake adequate, add some resistance training, and avoid very long daily fasts. On any diet, muscle loss comes mostly from too little protein and no strength work, not from fasting itself. FastTrack keeps your eating window consistent so it is easier to hit your protein.
Can I do intermittent fasting with diabetes? +
Talk to your doctor first. Fasting can change your blood sugar and the timing of medication, so anyone with diabetes should fast only under medical guidance. Once your provider approves, FastTrack can help you keep your windows and routine steady.
What are the health benefits of intermittent fasting? +
Research shows intermittent fasting can improve insulin sensitivity, reduce inflammation, promote autophagy (cellular repair), support heart health, enhance mental clarity, and aid weight loss. A 2023 study in the journal Nutrients found that intermittent fasting significantly improves metabolic health markers including blood pressure and cholesterol levels.

Start Your Transformation Today

Set your first fasting window in under 60 seconds. Track your fasts, follow a plan that fits you, and watch your progress add up.

Download on the App Store Get it on Google Play

Latest from the Blog & Glossary

Science-backed fasting guides, updated regularly.

Jul 13, 2026

What Intermittent Fasting Does to Your Body and Brain

Jul 13, 2026

Intermittent Fasting for Beginners: How to Start Step by Step

Jul 13, 2026

Intermittent Fasting Hours: How to Choose Your Fasting Window

Jul 13, 2026

Intermittent Fasting Side Effects: What to Expect and When to Stop

Mar 12, 2026

What Is Autophagy?

Mar 12, 2026

What Is Ketosis?

Mar 12, 2026

What Is Intermittent Fasting?

Mar 12, 2026

What Is 16:8 Fasting?

View all articles →   |   Browse glossary →

Scan to download FastTrack on your phone
Scan to download
iOS & Android