Best picks to start fasting
Our top tool and books, picked for beginners.
- Top pick · Free to startTry Zero
Zero fasting app
Time and log your fasts on your phone.
Best beginner bookBuy now at Bookshop.orgThe Complete Guide to Fasting
Jason Fung with Jimmy Moore
Best for womenBuy now at Bookshop.orgFast Like a Girl
Dr. Mindy Pelz
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Resources
Some adults, after they understand the basics, look for a clock, a food log, a book, or something to drink with a meal. Nothing on this page is required. The guides and tools on PureFasting stay free.
Some links on this page are affiliate links: the Bookshop.org book links and the “Try Zero” link. If you buy or sign up through them, PureFasting may earn a small commission at no extra cost to you. Items marked “Not an affiliate link yet” are examples only, with no link. PureFasting has no Amazon links. No purchase is required. This is not medical advice. Read the affiliate disclosure.
Fasting apps
A fasting app is a clock with labels. People look at one when they want a start time and an end time without doing the arithmetic. A paper note, or the timer on this site, does the same job.
Zero
A fasting tracker app with a timer for starting and ending your eating window and logging your fasts. Zero offers a 7-day free trial on iOS and Android, then a paid annual plan. Check the current price in the app store before you subscribe.
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YAZIO
Someone might find YAZIO useful if they want a fasting timer next to a place to note meals.
It is optional and not required. A notebook works for the same notes.
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Tracking tools
A food log is something people open when they want to see what they actually ate during an eating window. It is a poor fit if writing numbers makes you anxious. This site does not score your meals.
MacroFactor
Someone might find MacroFactor useful as a place to record meals and portions on eating days.
It is optional and not required. Memory or a paper list is enough to learn.
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Cronometer
Someone might find Cronometer useful when they want a written record of what they ate, beyond a fasting clock.
It is optional and not required. No guide on this site asks you to log food.
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Books to read at your own pace
A book can go deeper than one guide. These are well-known fasting books from different authors with different views. Nothing here is required, and the PureFasting guides and tools stay free.
PureFasting earns a small commission from Bookshop.org purchases, which supports independent bookshops, at no extra cost to you. Affiliate disclosure.
Books share their authors’ views and are not medical advice. Talk to a doctor before fasting if you are pregnant, breastfeeding, under 18, diabetic, on medication, or have a history of eating disorders.
The Complete Guide to Fasting
A practical handbook on different ways to fast, from shorter daily windows to longer fasts, with common questions answered along the way.
Good for: Beginners who want one clear, step-by-step overview.
See it on Bookshop.org →
The Obesity Code
Explains one doctor’s view of how hormones like insulin relate to appetite and body weight, and where meal timing fits in.
Good for: Readers curious about the “why” behind meal timing.
See it on Bookshop.org →
Fast Like a Girl
A fasting guide written for women, covering how the author suggests timing fasts around the menstrual cycle, with recipes for breaking a fast.
Good for: Women who want fasting info written with their hormones in mind.
See it on Bookshop.org →
Fast This Way
A biohacker’s take on intermittent fasting that also looks at sleep, exercise and food choices around an eating window.
Good for: People who like experimenting and reading about the latest ideas.
See it on Bookshop.org →
The Longevity Diet
A researcher’s overview of his work on nutrition and ageing, including everyday eating patterns and his periodic fasting-mimicking approach.
Good for: Readers who prefer a research-focused, long-term view.
See it on Bookshop.org →Meal and food resources
The eating window is still ordinary food. When a daily fast ends, a normal meal is enough. Broth and drink mixes are things some people look at. They are not part of learning this topic. See how to break a fast.
Kettle & Fire
Someone might find Kettle & Fire useful if they want a ready-made broth when they end a fast.
Ordinary food is enough. This broth is optional and not required.
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Ultima
Someone might find Ultima useful as an electrolyte drink mix they have seen while reading about hydration.
It is optional and not required. Water is the usual drink, and this site does not say you need a mix.
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Hydrant
Someone might find Hydrant useful as another electrolyte drink mix some people look at.
It is optional and not required. You do not need it to read these guides or to drink water.
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Safety. People who are pregnant, breastfeeding, under 18, have an eating disorder or a history of one, have diabetes or hypoglycemia, take medication, or have a heart, kidney, or other medical condition should talk with a healthcare professional before fasting. Stop a fast and get help if you feel faint, confused, or unwell.