Episode Details

Fasting is everywhere, but most people get it wrong. A fasting coach explains why your body benefits from a break from food, and how to start, what to eat, and how to break a fast properly.

Sinclair Fischer is a fasting coach who has spent the last 10 years guiding hundreds of people through fasts, most of them women. He was a young rugby player on the edge of going professional when a back injury stopped him in his tracks. After eight years of searching for answers, a 19-day water fast changed his relationship with his body and set him on a new path. He has since done multiple extended fasts himself, including a 40-day fast, and now shares what he’s learned from both the physical and the mental side.

In this episode, he explains:

■ The Injury That Started It All: How a light deadlift ended his rugby career, why years of changing what he ate didn’t help, and why he started focusing on what the body gets rid of rather than what goes in.

■ What Happens When You Stop Eating: How the body shifts from digesting to using stored sugar, into ketosis, and why he says your body is already in a “fasted” state when you wake up.

■ Fasting Isn’t a Weight Loss Hack: Why intermittent fasting won’t work if you overeat in your eating window, and why he thinks the focus should be on rest and repair instead.

■ The Fast That Broke Him: The retreat where he had panic attacks alone in a room with no support, why it was his most important experience, and why your body needs to feel safe.

■ Who Shouldn’t Fast: Why fasting isn’t right for everyone, including anyone pregnant, breastfeeding or with a difficult relationship with food, and why guidance matters.

■ Simple Ways to Start: Missing a single meal, pushing your first meal later, eating earlier before bed, and why breaking a fast slowly matters as much as the fast itself.

The views in this episode are the guest’s own and are not medical advice. Extended and water fasting should only be done under medical supervision. Speak to your doctor before changing your diet, especially if you have a health condition or take medication. If you’re struggling with food or eating, the Butterfly Foundation helpline is 1800 33 4673.

 00:36 Intro
 03:05 From Rugby Player to Fasting Coach
 06:21 The 19-Day Fast That Changed Everything
 11:09 Are Humans Built to Go Without Food?
 13:41 Why So Many Religions Fast
 17:41 The Different Types of Fasting
 19:52 Calorie Restriction and Longevity
 20:43 What Happens After You Eat
 22:50 What Happens in the First 12 Hours of a Fast
 24:27 Ketosis: When Your Body Switches Fuel
 26:26 Autophagy and What Happens After a Week
 31:53 Should You Exercise While Fasting?
 33:16 What Day 20 Really Feels Like
 36:01 The Fast That Broke Him
 41:44 Who Shouldn’t Fast?
 43:27 Does Fasting Help You Lose Weight?
 53:21 How to Fast in Everyday Life
 55:31 Does Coffee Break a Fast?
 57:46 What to Eat in Your Eating Window
 01:02:04 Should You Stop Eating Before Bed?
 01:02:42 The 5:2 Approach
 01:04:42 Where to Start
 01:06:53 The Power of Belief
 01:14:13 His One Tip
 01:15:47 The Biggest Myth About Fasting
 01:19:52 How to Break a Fast Safely

Questions asked in this episode (for reference):

• What led you from rugby player to fasting expert?
• What made you think fasting would help your back pain?
• How many fasts have you done since then?
• Is fasting a return to how our ancestors lived?
• Why do so many religions include fasting?
• What are the main types of fasting?
• What happens to the body after I eat?
• Does eating raise insulin?
• What happens in the first 12 hours of a fast?
• What happens after two or three days?
• Is ketosis what gives y