deprivation of leucine for fat loss

[jswain34]

Hey guys, I was looking for some articles for my genetics project and stumbled across this. I thought it was pretty interesting from what I skimmed through. I know it's a study in rats, and that humans are not rats, but its intriguing nonetheless. What do you guys think?

Heres the link to the study:

Leucine Deprivation Stimulates Fat Loss via Increasing CRH Expression in the Hypothalamus and Activating The Sympathetic Nervous System

Some of the major points I got out of the study were:

1. "leucine deprivation increases lipolysis in WAT and UCP1 expression in BAT"
2. "Based on these controls, leucine deprivation reduced fat mass (∼50%) and body weight (∼14%)"
3. "administration of leucine decreases levels of activated hormone sensitive lipase (HSL) in WAT and UCP1 (uncoupling protein 1) expression in BAT and significantly attenuates fat loss in leucine-deprived mice."
4. "we show that intracerebroventricular administration of leucine significantly attenuates abdominal fat loss and blocks activation of hormone sensitive lipase in WAT and induction of UCP1 in BAT in leucine-deprived mice. Furthermore, we provide evidence that leucine deprivation stimulates fat loss by increasing expression of corticotrophin-releasing hormone in the hypothalamus via activation of stimulatory G protein/cAMP/protein kinase A/cAMP response element-binding protein pathway."

 

[RecompMan]

I assume bc leucine stimulates mTOR which is anabolic and stimulates protein synthesis. There for when you remove an anabolic process a catabolic process would follow.

It makes sense. I haven't read the article so I don't know if it looked into muscle sparing

 

[jswain34]

I also considered that. And I realize that leucine is anabolic by way of mTOR. Just thought it was interesting because most people like to use bcaas/leucine in a cut to try and preserve muscle mass. But it could be somewhat hindering their fat loss. So wouldnt be much more ideal if another way to preserve muscle mass was used and then one could try to induce this deprivation and further their fat loss? That leads us to the question, what else is there that preserves muscle mass with a similiar level of effectiveness as leucine?

 

[xhrr]

But when trying to cut most opt for a diet higher in protein and moderate amounts of carbs and fat. Therefore they will still be consuming a sufficient amount of leucine through there diet alone.

 

[jswain34]

True..

 

[hvactech]

i would just assume to have to cut a little longer for my targeted fat loss then drop leucine

 

[ZiR RED]

Leucine is an insulinogenic amino acid. Insulin, as we well know, inhibits lipolysis.

I haven't read the article, but if you want to apply this, then just take leucine circa training. Inuslin release is inhibited by exercise, thus you will get the beneficial anabolic effects of the leucine without inhibiting lipolysis.

Br

 

[SonicSWOLE]

Leucine is an insulinogenic amino acid. Insulin, as we well know, inhibits lipolysis.

I haven't read the article, but if you want to apply this, then just take leucine circa training. Inuslin release is inhibited by exercise, thus you will get the beneficial anabolic effects of the leucine without inhibiting lipolysis.

Br

My belief was that Leucine was actually a Ketogenic Amino Acid. In contrast, your other 2 BCAA's (valine and isoleucine) are both Glucogenic, in which they can stimulate gluconeogenesis during a fasting period. I could be wrong, but that would seem to be contrary to being Insulinogenic.

 

[ZiR RED]

My belief was that Leucine was actually a Ketogenic Amino Acid. In contrast, your other 2 BCAA's (valine and isoleucine) are both Glucogenic, in which they can stimulate gluconeogenesis during a fasting period. I could be wrong, but that would seem to be contrary to being Insulinogenic.

You are part correct. Lue is ketogenic in how it is metabolized and then fed into the krebs cycle. But, lue intake also stimulates the release of insulin. I believe the other two BCAA's stimulate both the release of insulin and glucagon.

 

[SonicSWOLE]

You are part correct. Lue is ketogenic in how it is metabolized and then fed into the krebs cycle. But, lue intake also stimulates the release of insulin. I believe the other two BCAA's stimulate both the release of insulin and glucagon.

This has been bothering me all day, lol.....

Pancreas. 1991 Mar;6(2):221-8.

Effects of leucine on insulin secretion and beta cell membrane potential in mouse islets of Langerhans.

Brouwer AE, Carroll PB, Atwater IJ.


Source

University of Leiden, Faculty of Medicine, The Netherlands.


Abstract


Leucine is known to enhance insulin secretion from islets of Langerhans, and insulin promotes leucine uptake in peripheral tissues. The present studies were designed to elucidate the effects of leucine on glucose responsiveness and stimulus secretion coupling in mouse islets of Langerhans. The effects of 20 mM leucine on insulin secretion and membrane potential were studied over a range of glucose concentrations (0-27.7 mM). Microdissected, perifused pancreatic islets from normal adult mice were used for both studies of insulin secretion and electrophysiology in order to make a close comparison between these measurements. Leucine enhanced the insulin secretion in the presence of 5.6, 11.1, and 22.2 mM glucose. In the presence of leucine, 27 mM glucose inhibited insulin secretion. In the absence of glucose-leucine did not induce electrical activity of the beta cell membrane, whereas in the presence of 5.6, 11.1, and 22.2 mM glucose leucine increased spike frequency. Thus, leucine shifts both the glucose-dependent insulin secretion and electrical activity toward lower glucose concentrations. It is concluded that leucine and glucose share a common metabolic pathway (citric acid cycle) for stimulatory effects. Leucine is deaminated to form 2-ketoisocaproic acid (KIC) and produce NH4+. We propose that in the absence of glucose this increases cytosolic pH, which in turn increases K+ permeability, and inhibits electrical activity and insulin secretion.


PMID: 1886890 [PubMed - indexed for MEDLINE]


Publication Types, MeSH Terms, Substances


This seems to me, that Leucine actually does not stimulate insulin in the absence of glucose, as a matter of fact it appears that Leucine actually inhibits insulin secretion. Which as I am on a ckd, I find useful.

 

[mr.cooper69]

This has been bothering me all day, lol.....

Pancreas. 1991 Mar;6(2):221-8.

Effects of leucine on insulin secretion and beta cell membrane potential in mouse islets of Langerhans.

Brouwer AE, Carroll PB, Atwater IJ.


Source

University of Leiden, Faculty of Medicine, The Netherlands.


Abstract


Leucine is known to enhance insulin secretion from islets of Langerhans, and insulin promotes leucine uptake in peripheral tissues. The present studies were designed to elucidate the effects of leucine on glucose responsiveness and stimulus secretion coupling in mouse islets of Langerhans. The effects of 20 mM leucine on insulin secretion and membrane potential were studied over a range of glucose concentrations (0-27.7 mM). Microdissected, perifused pancreatic islets from normal adult mice were used for both studies of insulin secretion and electrophysiology in order to make a close comparison between these measurements. Leucine enhanced the insulin secretion in the presence of 5.6, 11.1, and 22.2 mM glucose. In the presence of leucine, 27 mM glucose inhibited insulin secretion. In the absence of glucose-leucine did not induce electrical activity of the beta cell membrane, whereas in the presence of 5.6, 11.1, and 22.2 mM glucose leucine increased spike frequency. Thus, leucine shifts both the glucose-dependent insulin secretion and electrical activity toward lower glucose concentrations. It is concluded that leucine and glucose share a common metabolic pathway (citric acid cycle) for stimulatory effects. Leucine is deaminated to form 2-ketoisocaproic acid (KIC) and produce NH4+. We propose that in the absence of glucose this increases cytosolic pH, which in turn increases K+ permeability, and inhibits electrical activity and insulin secretion.


PMID: 1886890 [PubMed - indexed for MEDLINE]


Publication Types, MeSH Terms, Substances


This seems to me, that Leucine actually does not stimulate insulin in the absence of glucose, as a matter of fact it appears that Leucine actually inhibits insulin secretion. Which as I am on a ckd, I find useful.

There is human data showing a mild insulin release from leucine. That is much more relevant than an in vitro study using mouse islets of langerhands. Leucine is beneficial in CKD because it converts to the energy substrate that your body is adapted for (ketones). The release of insulin precedes uptake and metabolism of leucine...they are two different concepts. Here is a nice review on the topic: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2969169/

Also, leucine likely "inhibits" fat loss due to mTOR signaling and subsequent deactivation of AMPK. There is no reason to "deprive" yourself of leucine while cutting unless you consider mTOR the devil. In which case, prepare to lose all muscle mass

 

[gymratluke]

Great info in this thread!! I would never drop Leu when dieting tho. I have always cut using mega doses BCAA's and I use a Leu powder to get an ever high ratio then the typical 2:1 found in most forumulas, and I have never had any kind of issue with fat loss being hindered. If anything, I keep almost all my strength and muscle, even when dieting down to sub 5% bf, which is hard to do for anyone. I've always given all the credit to the BCAAs