Life in the Fasting Lane: The Essential Guide to Making Intermittent Fasting Simple, Sustainable, and Enjoyable

by Jason Fung

Being fat is a problem with my hormones. What I eat and when I eat affects my hormones. Therefore, if I change those two things, I can lose weight.

Now I understand that my body can either be focused on storing energy or burning energy. But not both at the same time.

When I eat often, my body becomes busy packing away energy as fat. When I eat less often, my body has more time to burn energy—and fat.

Fasting allows my body to focus its efforts on using energy inste...

The body stores food energy in two different ways: as sugar and as body fat.

When we eat carbohydrates, some of this sugar is used by cells in the kidneys, liver, brain, and more.

If there are carbs left over, they’re stored in the liver as glycogen, another chain of sugar.

Glycogen is easy to use and simple for the liver to process, but the liver has limited space to store it.

Body fat is harder to get to and more difficult for the liver to break down, but it offers the advantage of unlimited storage space

Think of glycogen as a re...

Think of body fat like a basement deep freezer.

High levels of insulin tell the body to keep trying to store food energy, preventing us from burning our fat stores.

We are, in essence, continuing to restock the refrigerator, while wondering why our basement freezer is bursting at the seams.

fasting regulates your hormones. It’s more than a diet; it resets your body’s internal controls, allowing it to burn the right amount of energy to keep you alive.

By not eating, we allow insulin levels to drop, which tells the body that food is no longer available and that it’s time to eat some of the food in the fridge (glycogen) or freezer (body fat).

The key is to control hunger and maintain basal metabolic rate. In order to do that, we must eat foods that increase satiety hormones and keep insulin (fat-storing hormone) low.

Fasting induces autophagy—a cellular process that helps the body clear out old or damaged cell parts—and,

breast cancer cells proliferate with high levels of insulin and die without it. What lowers insulin levels? Fasting.

When insulin is too high for too long, the body stores more body fat than it needs to.

Cells become overloaded with glucose, and they become resistant to insulin.

Glucose from the blood can no longer go into the cells, and blood glucose ...

When the liver is overloaded with glucose, excess sugar gets stored as fat, a...

Since metabolic syndrome is a disease of too much insulin, lowering insulin levels is critical to reversing it.

Refined carbohydrates cause the greatest increase in insulin, so eating a diet low in refined carbs and sugar is a great start.

The main satiety hormones are peptide YY, which responds primarily to protein, and cholecystokinin, which responds primarily to dietary fat.

The problem becomes amplified if we are eating, as most people are, processed and refined carbohydrates.

When you consume refined carbs, your blood sugar levels skyrocket, telling your pancreas to produce a surge of insulin.

The job of insulin is to tell your body to store food energy as sugar (glycogen i...

That huge spike in insulin immediately diverts most of the incoming food energy (calories) in...

This leaves relatively little food energy for metabolism. Your muscles, liver, and brain are still crying out for glucose for energy, and you get hungr...

There are three distinct ghrelin peaks, corresponding to lunch, dinner, and the next day’s breakfast, suggesting that hunger can be a learned response.

We are used to eating three meals per day, so we begin to get hungry just because it is “time to eat.”

But if you don’t eat at those times, ghrelin does not continually increase. After the initial wave of hunger, it recedes, and it spontaneously decreases ...

Your average ghrelin levels over twenty-four hours of fasting decrease, meaning that eating nothing over a long period of time makes you less hungry.

you don’t regulate your appetite on a hormonal level, you’ll never regain control, no matter how small your stomach is.

Weight loss, at its core, is not about controlling calories, it’s about controlling hunger.

Fasting offers a unique solution. Randomly skipping meals and varying the eating intervals helps break our current habit of feeding three to six times a day.

Switching habits instead of going cold turkey will be easier in the long run.

Fasting has given me back control over my body.

I can’t even describe how much that empowers me.

Part of me is still sad from time to time that I had to struggle with th...

Part of me is angry at the world for the state of our e...

What calms me down is knowing that there is something I can do about it, and that I can teach others ho...

Hunger is often associated with the time of day you’re used to eating, a place, or an occasion.

Eat only at the table. No eating at your desk. No eating in the car. No eating on the couch. No eating in bed. No eating during class. No eating at the movies or at a sporting event.

Why would our hormones control everything in our body but fat cells?

It’s calorie-restriction diets that cause your metabolism to slow down to a crawl.

Fasting does just the opposite.

The hormone noradrenaline, which is produced during a period of fasting, ...

As you fast more and regularly over time, metabolic rates go up, and more w...