If one is thinking about following an IF-program, then what is the best approach? I'll go into some of the details Todd Becker provides in his lecture, but first there's a key point to remember. It's not about losing weight; The key is to adapt the body to be able to run on its stored fuel. This can only be done by allowing the body to do it. Let's go through the science of this process.

How much energy do we have?

Blood	Glucose	5	20	20 min	10 min
Glycogen (liver + mustcle)	Glucose	1000	4000	67 hours	33 hours
Adipose tissue	Fat	15.000	135.000	94 days	47 days

In your bloodstream you have about 5 grams of glucose, which is only about a theespoon of suger. That will last you 10 minutes if you're very active, and 20 minutes if you're not.

The next thing is glycogen, which is in your liver and mustles. You have 1 kg of it, which will last you a day and a half to three days. Atlethes know this and they 'carb up' and build up their glycogen. It will mostly store in the backside, the belly, the thighs,.. You got about 15 kilograms of adipose tissue / 135.000 calories. Depending on your activity level it will last you a month and a half to three months.

So we can actually survive without eating, although this is for most people uncomfortable because their body hasn't adapted to it. Think of the following analogy. Access to energy: The tanker and the mini:
- Think of an obese person as a gesoline tanker with a huge energy reservoir, but which must refuel every 2 miles.
- Think of the lean athlete as a mini with a similar energy reservoir, but more energy and endurance.
- How is that possible? Why can't the tanker access all that fuel?

Insulin response to carbohydrates in lean and obese subjects

Well, alot of it has to do with insuline systems. Here you see a chart of a study showing the level of insuline in the blood. You see the insuline level is shooting up several times during the day with overweight persons. What does that mean during the course in the day? Read on..

Insuline response to meals in lean and obese subjects

The green is the meals. Everytime you eat a meal, you bump up. The yellow is where you are buring fat. Quess when we burn most of our fat? During our sleep.. Assuming you stop eating around 7-8 pm until noon, you have a significant amount of fat mobilization while you sleep. You can proof this yourself by weighing yourself at night and the next morning. Or get your own insuline meter.

An overweight person has unfortunately a higher base of insuline level. As you can see in the chart the obese person starts out the day with barely an ability to burn fat, the response is much higher and immediately everything they eat is being stored as fat. It's making you hungry all the time because it's depleting the fats and suger out of the bloodstream.

Insuline response to meals: Meal frequency

Taken the same plots and showing them in an individual eating six small meals a day, somebody eating three meals and someone eating two meals a day. Although an individual who consumes 6 meals a day has relatively lower insuline levels without peaks, it is never aloud to lower down in the fat burning zone. Consuming three meals a day (without snacks) is pretty balanced. Eating 2 meals a day, not too far from each other, is getting to intermittent fasting. So lets say you stop eating around 8 pm until noon the next day, you have 16 hours of burning fat, glycogen, lowered insuline levels and health benefits.

Why IF fasting works

• Sustained low insulin levels allow:
  - Improved acces to glycogen stores by increasing glucagon and adrenaline levels (= release of the suger from the mustle)
  - Improved access to fat stores by reducing lipoprotein lipase (LPL) and increasing Hormone Sensitive Lipase activity (HSL) (= allowing the fat coming out of your adispose tissue + used as fuel)
  - Access to ketones (= another useful energy source)
• Regular fasting for short periods will gradually increase the speed and extent of these adoptations
• Instead of running largely on one fuel (glucose/suger), you will become a "flex fuel" vehicle that can run as easy on glucose, fat or ketones.

I don't claim any credit for this article. This is from Part 4 of 5, from a lecture by Todd Becker, delivered on May 18, 2011 at The Third Door In Palo Alto, California. For more background visit http://bit.ly/mDaAmM

Tags: autophagy, BDNF, calorie restriction, deconditioning diet, fast-5, fasted workouts, fat loss, Hormesis, insulin, intermittent fasting, longevity, Martin Berkhan, mitohormesis