The Obesity Code: Unlocking the Secrets of Weight Loss (Why Intermittent Fasting Is the Key to Controlling Your Weight)

by Jason Fung

Long-term weight loss is really a two-step process.

Two major factors maintain our insulin at a high level. The first is the foods that we eat—which are what we usually change when we go on a diet.

But we fail to address the other factor: the long-term problem of insulin resistance. This pr...

Insulin resistance keeps our insulin levels high. High insulin maintains ou...

To break the insulin-resistance cycle, we must have recurrent periods of very low insulin levels.

We know that eating the proper foods prevents high levels, but it won’t do much to lower them.

The answer we are looking for is, in a word, fasting.

When we talk about fasting to break insulin resistance and lose weight, we are talking about intermittent fasts of twenty-four to thirty-six hours.

GLUCOSE AND FAT are the body’s main sources of energy. When glucose is not available, then the body adjusts by using fat, without any health detriment.

What we’re describing here is the process the body undergoes to switch from burning glucose (short term) to burning fat (long term).

Fat is simply the body’s stored food energy. In times of food scarcity, stored food (fat) is naturally released to fill the void.

The body does not “burn muscle” in an effort to feed itself until all th...

It’s crucial to note that all these beneficial adaptive changes do not occur in the calor...

Regular fasting, by routinely lowering insulin levels, has been shown to significantly improve insulin sensitivity.8 This finding is the missing piece in the weight-loss puzzle.

The better question would be why the human body would store energy as fat if it planned to burn protein instead.

Fat is the body’s way of storing food energy for the long term; it uses glucose/glycogen in the short term.

When short-term stores are depleted, the body turns to its long-term stores without problem.

Daily caloric restriction does, in fact, lead to decreased metabolism, so people have assumed that this effect would be magnified as food intake dropped to zero.

Decreasing food intake is matched by decreased energy expenditure.

However, as food intake goes to zero, the body switches energy inputs from fo...

Detailed physiologic measurements show that total energy expenditure is increased over the duration of a fast.

Twenty-two days of alternate daily fasting created no measurable decrease in total energy expenditure.

Fat oxidation increased 58 percent, while carbohydrate oxidation decr...

Reduce intake of refined grains and sugars, moderate protein consumption and increase natural fats.

Maximize protective factors such as fiber and vinegar. Choose only natural, unprocessed foods.

balance insulin-dominant periods with insulin-deficient periods: balance yo...

Longer fasting periods produce lower insulin levels, greater weight loss and greater blood sugar reduction in diabetics.

Stress relief is an active process. Meditation, tai chi, yoga, religious practice and massage are all good choices.

Regular exercise is an excellent way to relieve stress and lower cortisol levels.

The original intent of the fight-or-flight response was to mobilize the body...

Exercise can also release endorphins and...