IF, Insulin Sensitivity and Fat Loss

[AngloSaxonMMA]

I have been making great gains from intermittent fasting both in fat loss and lean gain runs.

I understand what it does and how it works, but I don't get why it works.

The whole idea is fasting increases your insulin sensitivity so you eat when you have minimal insulin resistance, therefore you need less insulin and have less in the blood to transfer blood glucose to fat cells. This results in less fat storage.

However, when you are more insulin sensitive (ectomorph perhaps?) where does the excess blood glucose go? Does it just mean you store more as glycogen in the liver? Or do you just excrete excess calories rather than storing them as fat, due to the reduced amount of calories available? Or do you maintain a higher blood-glucose or have more fat in your blood (triglycerides?) which you then use as fuel?

I've read the majority of leangains.com but it doesn't seem to explain this.

Many Thanks

[dmacdonal9]

From what little I know, increasing insulin sensitivity has less to do with losing fat, and more to do with building muscle. Insulin is anabolic, so increased insulin sensitivity helps you preserve and gain lean mass.

I don't think it's correct to assume that increased insulin sensitivity means decreased fat storage. I think it just means that your body needs less insulin to get the job done of clearing out excess glucose from the blood. It all still has to go somewhere, either into glycogen stores or fat cells.

So on the flip side, if you are insulin resistant, your body produces more insulin to get the glucose storing job done, but it's also more resistant to the anabolic effects of insulin, which is a bad thing.

That's my impression anyway, I'm not sure it's right.

[AngloSaxonMMA]

From what little I know, increasing insulin sensitivity has less to do with losing fat, and more to do with building muscle. Insulin is anabolic, so increased insulin sensitivity helps you preserve and gain lean mass.

I don't think it's correct to assume that increased insulin sensitivity means decreased fat storage. I think it just means that your body needs less insulin to get the job done of clearing out excess glucose from the blood. It all still has to go somewhere, either into glycogen stores or fat cells.

So on the flip side, if you are insulin resistant, your body produces more insulin to get the glucose storing job done, but it's also more resistant to the anabolic effects of insulin, which is a bad thing.

That's my impression anyway, I'm not sure it's right.

I thought it was the other way round with being resistant, its good for muscle building as you say due to being so anabolic. But then it is not disadvantage to have normal/healthy high insulin sensitivity since you can still spike it with pwo carbs and protein anyway.

[dmacdonal9]

Lyle has something on this, the background anyway: http://www.bodyrecomposition.com/fat...-fat-loss.html

[Electricheadd]

The theory is a bit more complex than that but it boils down to the idea that fasted training improves nutrient partitioning through improved insulin sensitivity. Its more about muscle gain than fat loss and needs more research but its promising.

http://www.leangains.com/2010/09/fas...nsitivity.html

[LiftHeavy3400]

Being insulin resistant ISN'T good for making muscle gains, if you're insulin resistant, less carbohydrates will be stored in muscle glycogen, and more will be potentially go through fat storing pathways.

Therefore I think it would be reasonable to assume increased insulin sensitivity means decreased fat storage... Correct me if i'm wrong. Could be one of the reasons why so many people see improved body recomposition when supplementing with Glycobol and ALA.

[mpipes]

When you're insulin sensitive, insulin can effectively scrub glucose from the bloodstream and push it into BOTH muscle and fat tissue. Remember if you're partially glycogen depleted, that includes glycogen stored in fat cells just as well as muscle.

It's training that helps to partition that refilled glycogen back into muscle.

[Kostya1981]

However, when you are more insulin sensitive (ectomorph perhaps?) where does ...
Many Thanks

Actually, ectomorphs are more insulin resistant for carbs/whey. That is why they hardly gain weight, and need "gainer protein type" for building mass.
Insulin sensitivity persons (endomorphs) are easy gain mass with only "whey iso 100%".