Increasing Dietary Leucine Intake Reduces Diet-Induced Obesi

[Gregor]

Increasing Dietary Leucine Intake Reduces Diet-Induced Obesity and Improves Glucose and Cholesterol Metabolism in Mice via Multimechanisms

Yiying Zhang1,2, Kaiying Guo1, Robert E. LeBlanc1, Daniella Loh1, Gary J. Schwartz3, and Yi-Hao Yu4

1 Department of Pediatrics, Division of Molecular Genetics, Columbia University, New York, New York

2 Naomi Berrie Diabetes Center, Columbia University, New York, New York

3 Department of Medicine and Neuroscience, Diabetes Research and Training Center, Albert Einstein College of Medicine, Bronx, New York

4 Department of Medicine, Division of Preventive Medicine, Columbia University, New York, New York

Leucine, as an essential amino acid and activator of mTOR (mammalian target of rapamycin), promotes protein synthesis and suppresses protein catabolism. However, the effect of leucine on overall glucose and energy metabolism remains unclear, and whether leucine has beneficial effects as a long-term dietary supplement has not been examined. In the present study, we doubled dietary leucine intake via leucine-containing drinking water in mice with free excess to either a rodent chow or a high-fat diet (HFD). While it produced no major metabolic effects in chow-fed mice, increasing leucine intake resulted in up to 32% reduction of weight gain (P < 0.05) and a 25% decrease in adiposity (P < 0.01) in HFD-fed mice. The reduction of adiposity resulted from increased resting energy expenditure associated with increased expression of uncoupling protein 3 in brown and white adipose tissues and in skeletal muscle, while food intake was not decreased. Increasing leucine intake also prevented HFD-induced hyperglycemia, which was associated with improved insulin sensitivity, decreased plasma concentrations of glucagon and glucogenic amino acids, and downregulation of hepatic glucose-6-phosphatase. Additionally, plasma levels of total and LDL cholesterol were decreased by 27% (P < 0.001) and 53% (P < 0.001), respectively, in leucine supplemented HFD-fed mice compared with the control mice fed the same diet. The reduction in cholesterol levels was largely independent of leucine-induced changes in adiposity. In conclusion, increases in dietary leucine intake substantially decrease diet-induced obesity, hyperglycemia, and hypercholesterolemia in mice with ad libitum consumption of HFD likely via multiple mechanisms.

[Gregor]

Leucine-enriched nutrients and the regulation of mammalian target of rapamycin signalling and human skeletal muscle protein synthesis.

Curr Opin Clin Nutr Metab Care. 2008 May;11(3):222-6

Authors: Drummond MJ, Rasmussen BB

PURPOSE OF REVIEW: To highlight recent studies that have examined the cell-signalling mechanisms responsible for the amino acid (primarily leucine and the essential amino acids) stimulation of human skeletal muscle protein synthesis. RECENT FINDINGS: Ingestion of a leucine-enriched essential amino acid nutrient solution rapidly and potently activates the mammalian target of rapamycin signalling pathway and protein synthesis in human skeletal muscle. Further, mTOR signalling and muscle protein synthesis are enhanced when leucine-enriched nutrients are ingested following resistance exercise. The addition of leucine to regular meals may improve the ability of feeding to stimulate protein synthesis in old human muscle. SUMMARY: Leucine and essential amino acids appear to stimulate human muscle protein synthesis primarily by activating the mammalian target of rapamycin signalling pathway. How human muscle cells sense an increase in leucine and/or essential amino acids to activate mammalian target of rapamycin signalling is currently unknown. Recent work, however, suggests that the kinases hVps34 and MAP43K may be involved. Leucine-enriched essential amino acid ingestion, in combination with resistance exercise in some cases, may be a useful intervention to promote mTOR signalling and protein synthesis in an effort to counteract a variety of muscle wasting conditions (e.g. sarcopenia, cachexia, AIDS, inactivity/bed rest, sepsis, kidney failure, and trauma).

[Gregor]

Effects of leucine and whey protein supplementation during eight weeks of unilateral resistance training.

Coburn JW, Housh DJ, Housh TJ, Malek MH, Beck TW, Cramer JT, Johnson GO, Donlin PE.

Department of Kinesiology, California State University, Fullerton, Fullerton, California 92834, USA. jcoburn@unlserve.unl.edu

The purpose of this study was to determine the effects of resistance training in combination with a leucine and whey protein supplement or a carbohydrate placebo on strength and muscle cross-sectional area (CSA). Thirty-three men (mean age +/- SD = 22.4 +/- 2.4 years) were assigned to 1 of 3 groups: (1) supplementation group (SUPP), (2) placebo group (PL), or (3) control group (CON). The SUPP and PL performed unilateral training of the leg extensor muscles with the nondominant limb for 8 weeks. The strength of each limb, muscle CSA of the quadriceps femoris (QF), and body composition were assessed pretraining and posttraining. The results indicated significant increases in strength for both limbs in the SUPP but only the trained limb in the PL. The increase in strength for the trained limb of the SUPP was greater than that for the trained limb of the PL. There was no significant increase in strength for either limb in the CON. There were significant increases in the CSA of all muscles of the QF of the trained limb for the SUPP and PL, and of the vastus lateralis of the untrained limb for the SUPP. The increases in QF CSA did not differ between the SUPP and PL. No significant CSA changes were found for either limb in the CON. There were no significant changes in body composition for the SUPP, PL, or CON. The current findings suggest that leucine and whey protein supplementation may provide an ergogenic effect which enhances the acquisition of strength beyond that achieved with resistance training and a carbohydrate placebo.

[aoa]

so, should we take leucine in supplaments or just eat stuff that has it?

[Emil Brannmark]

The studies mentioned don't really lend any credible support to the use of leucine as supplementation. The first one is done on rats, and is thus more of a hypothesis forming type study and definitely not generalizable to humans. The second is a study on protein levels and not performance or other hard endpoints. The third is done with an intervention of both whey and leucine, and thus you can't really draw conclusions about leucine specifically from it. Don't understand why they chose that study design, but that's how it is.

[shinobi1]

Sorry I dont mean to be rude but if you want to reduce obesity all you need to do is eat right...

If you eat a diet that is mainly fruits and veggies then I can gaurentee you will eat less calories but you will be accually eating more food...

Strange huh? eat more, lose weight!

[Quick Start Test Smith]

Sorry I dont mean to be rude but if you want to reduce obesity all you need to do is eat right...
If you eat a diet that is mainly fruits and veggies then I can gaurentee you will eat less calories but you will be accually eating more food...
Strange huh? eat more, lose weight!

Eating a ton of vegetables is not the right way to lose weight and increase health for everyone. There are different nutritional types: carb types, protein types, and mixed types. Dr. Mercola (mercola.com) has a great free test at his website to help determine what type you are. One size does not fit all...

EDIT:

Oh gosh...

 

EDIT 2:

Although not everyone is the same type, I do not endorse Mercola's view on "carb types, protein types, and mixed types." That is such bunk. lol Eat a lot of vegetables...

[myphed]

I use Leucine in many of my weight loss programs, it does work! Great discussion! If you have any questions please feel free to contact me through my website.

Dr. Bird

http://www.transformyouaz.com

[Cole Dano]

Leucine is pretty inexpensive so its not a big deal to experiment with. I had good results using it to 'enrich' whey protein.

[Kevin Conley]

Why is this pinned??

[TrojanHorse]

Very interesting.  I usually take leucine (just a cheap, no-name brand) immediately post-workout with a whey protein & water shake.  The insulin spike and metabolic effect of the leucine acts like a "conductor" so to speak.  Think of the leucine as the light switch and the protein as the electricity.  The switch has to be on for the electricity to run.  Now, obviously you don't have to take leucine, but it definitely helps with transport of the protein.  Nice post.