The Real Reason Intermittent Fasting Gets You Results

5 min read

   Article At A Glance

  • Fasting allows the body to stick to the circadian rhythm.
  • Digestive organs are able to turn off overnight, enabling them to store energy optimally.
  • This in turn decreases inflammation and turns on the switch for fat burning.

You might still be wondering whether intermittent fasting actually provides any benefits that you can’t get from your standard put-food-on-the-scale and calorie counting diet. And while it isn’t necessarily going to be the fix-all miracle diet, there’s one particular mechanism that gives it an edge over other diets. Fasting gives your digestion some much-needed time off.

Here’s the thing, it’s not just your brain that operates on a 24-hour clock. This is known as a circadian rhythm, and that’s what stops you from pulling all nighters. Your liver, pancreas, the kidneys, they’re all on a schedule that repeats each day. And just like the brain, they need periods of inactivity in order to function properly.

Constant snacking, which is thoroughly a modern invention, works against the natural digestive rhythm, forcing the organs to work overtime. It’s much like trying to get by on 5 hours of sleep

When you dart down to the kitchen and have that one slice of cheese, that’s still going to extend the schedule by a few hours. Even when it’s just a bite, there are long-lasting consequences.

These organs need to clean up after each meal, and if they’re keeping busy into the night, they’ll be doing a shoddy job when it’s time to resume duties in the morning. Insulin levels rise as a result of the body being unable to dispose of incoming glucose, cellular recycling gets interrupted, and fat storage becomes much more likely

The circadian rhythm that runs the body is much like having traffic lights positioned at a busy intersection. If they’re constantly set at green, and unable to periodically turn off, a mess of congestion is inevitably the result. This process ages the body, driving up inflammation, and reducing its functional capacity.

And this is where intermittent fasting is perfectly positioned to swoop in and stop you reaching for the zimmer frame. But you don’t have to get to 16 hours just to have a healthy effect.

Even if you didn’t go the full 16 hours of an intermittent fasting schedule, and threw in the towel after scraping 12, that’s still going to make a huge difference. Because for many of us, food gets shovelled in last thing at night, and as one of the first actions of the morning. The ‘fasting window’ is closer to 8. Which is nowhere near enough time for the digestive organs to clean up from the previous night.

But 16 hours happens to be the sweet spot for giving the body time off, and that’s we’ll be aiming for in Bulletproof Fasting. At 16 hours, the digestive system will be able to function optimally, and with better energy storage, the body can prioritise building muscle and burning fat.

Here’s a study that demonstrated the beneficial effects of time restricted eating. These groups of mice were both put on what would be considered a “Western Diet”, a diet that is high in both dietary fats and carbohydrates. 

One group was restricted to eating within an 8-12 hour window and the other group could eat ad libitum (as much as they wanted), without calorie restriction. 

Mice who were restricted to 12-hour feeding showed:

  • Decreased fat mass in animals fed an obesogenic diet
  • Increased lean muscle mass in mice fed a normal diet
  • Improved in glucose tolerance and insulin sensitivity
  • Reduced inflammation, improved in lipid profile, and generally favourable changes in gene expression
  • Increased mitochondrial volume, especially in the liver and brown fat and an increased production of ketone bodies
  • Protection from mild-age related hepatic steatosis (fatty liver)

Mice restricted to 9 hours showed:

  • Increased endurance in the context of aerobic exercise (this effect was not seen in a feeding window above 9 hours)

The important thing to realise here, is that the mice in the study were having plenty of non-nutritious food. The type of food didn’t play any part. The change was only in when they ate. So If you want to actually feel as athletic as you’re trying to look, then you need to start thinking about the timing of foods. 

The fact that a circadian rhythm exists in the organs means that the best diet should involve a consistent schedule. And this is specifically your first and last meals. Pick a time and stick with it, and on each day if you can. 

Writing off the weekend and having late-night calories as a treat is only going to upset the rhythm and cost you on Monday. The benefits of sticking to your body clock are going to be at their best if you can stick to the schedule seven days a week. That’s why I’ve set Bulletproof Habits as a daily fixture. Same time, each day, repeating ad finitum. It won’t feel like a sacrifice once the effects start settling in.

If you haven’t already checked out Week 1 and 2 of the Bulletproof Fasting guide, you can check them out here and here.

Week 3 Bulletproof Fasting Walkthrough

1. Plan your last meal to take place at least three hours before bedtime. Yes, we’ve upped it an hour since last week.

2. Start the stopwatch after the last meal.

3. The first meal of the day should be at least 14 hours after the last meal.

4. Drink plenty of water, tea, coffee, to get there. Just don’t add milk or sweeteners. Just suck it up and keep things minimal.


How’s your fasting been faring so far during the lockdown? Share your thoughts in the comments, and subscribe below for more useful content. Thanks for reading.

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