Fasting Fat Loss and Why Doing It Well

Many think that not eating at regular intervals (every three hours according to some) causes the body enters a state in which they begin to feed on their own muscles to get the energy you need (catabolic state).

In fact, to lose muscle when you do not eat depends on how long you've been out to eat and what you were doing when they eat. A short fast of 16-24 hours will not result in loss of muscle. For energy the body first draw on the reserves of sugar (glycogen), then stored fat, and ultimately to the muscle.

Also if you are performing some form of exercise during fasting, the body is sufficiently "ready" to know that you need muscle to do the exercise, and it is preferable to get rid of fat.

In ancient times man had to physically work to eat (in the field, hunting, gathering etc.). And it was so easy to find food to eat every three hours. Sometimes they could spend many hours or even days. Why would the body get rid of the working tool (muscles) that helped him get food first instead of getting rid of fat that's what they are?.


Scientific Studies
One study took a group of men who got out 1000 calories to the diet consumed daily, while they did weight training 3 times a week. The result was they lost 9lbs of fat while kept all his muscle mass.

    Study: Rice B, Janssen I, Hudson R, Ross R. Diabetes Care 1999, 22: 684-691. Note the chart on page 4. There are three groups: diet only (DO), diet and aerobic exercise (DA) and diet and exercise by Force (DR). Changes in muscle mass (muscle Skeletal) were negative in the diet-only group, but there was a slight increase in the other groups. The study lasted 16 weeks.

Another study of 12 weeks with a very low calorie diet, specifically liquid only 800 calories per day. But because the study subjects trained with weights 3 times a week, kept all his muscle mass.

    Study: Bryner RW, Ullrich IH, Sauers J, Donley D, Hornsby G, Kolar M, et al. Effects of resistance vs.. aerobic training Combined With An 800 calorie liquid diet on lean body mass and resting metabolic rate. J Am Coll Nutr. 1999, 18:115-21.

Although these studies focus on caloric restriction and fasting in itself, the restriction is big enough to take them into account. A diet of 800 calories for 12 weeks is much more restrictive than make 2 fasts of 24 hours per week and still not lose muscle.

Martin Berkhan sums up a little bit about the myth of muscle loss during fasting:

Basically, while you're eating a decent amount of protein every 24 hours you will be completely well, without losing muscle.


When Fasting, Is the Body "Save" Fat?
Some people think that this is so, using the following logic: As the body senses that food is not moving, trying to protect fats to feed them and "manage them" anymore.

However, the reason for the body to store fat is none other than to store energy. And it is stored for eventual case that the food is lacking and that energy is needed. So when food is lacking it is natural to the body to use stored fat for what they are: energy.

It's simple. It is the way of work for the body design: Food gives energy to the various activities, fat is a way to store and stored to be used precisely where it is needed.

In fact, the speed at which your body burns fat increases during a short-term fasting and again points us Leangains Martin.

    "Reviewing the many studies I've read, the earliest evidence of a decrease in metabolic rate in response to fasting was after 60 hours (-8% in metabolic rate at rest). Other studies show that metabolism is not affected until 72-96 hours have passed (George Cahill has contributed much to this topic).

Add to this the fact that brakes automatically fast the calories you eat, the increase in metabolism and fewer calories are an excellent position to lose fat, not to "save it".


An Interesting Case Far
In 1968, a 27-year-old with extreme obesity (207 kg) underwent a medically supervised fasting. During fasting only drank water and took vitamins. Do not eat or drink anything for 1 year and 2 weeks! (Link to study)

Of course this man if you entered a completely catabolic and burned some muscle. But we are talking about a whole year without eating. In fact we can be sure that most of what burned was fat why are we so sure? Although it rose from 207 kg (456 pounds) despite 81 kg (180 pounds). Nobody can lose as many kilos of muscle and stay alive.

Rebound Effect
In addition, 5 years after the study, the patient had gained only 2.72 kg. This indicates that fasting does not have to produce a "rebound" when to leave it, in which all earn back the lost kilos.

Apart from this, there was no damage to health in this patient, despite making a fast as extreme (albeit supervised). Of course not recommended to fast so long, just as an example of extreme case. To implement a protocol focused on losing fat fast may be sufficient to fast 24 hours (one day's dinner until dinner the next) one or two days a week.


Conclusion
    The fasts of short duration (16-24 hours) primarily burn fat, not muscle.
    The short-term fasting does not cause the body to "save fat."
    The fasts of short duration will not cause "rebound effect" unless, of course, you eat too strong to break your fast.
    Fasted for 24 hours or less is insignificant compared to what the body can withstand.

Just do NOT recommended to fast food or water over 24 hours without further medical supervision. This time period is more than enough to get benefits of fasting. You do not need to lose weight and may be counterproductive exceeded leading to eating disorders.

For more information about the different types of controlled fasting can visit and how to implement the Controlled Fast post on our forum