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Leucine and BCAAs (branched chain amino acids)

BCAAs can be obtained through the internet. Please see related topics that provide supporting evidence on the high protein diet, and a recent article A high-protein diet induces sustained reductions in appetite.

An article May 12, 2006 indicates that a key to appetite suppression and weight loss may be getting enough of an amino acid found in protein called leucine. Just as carbohydrates are polysaccharides made of many sugar molecules, proteins are polyamino acids, made of about 22 different amino acids. In the article cited below, the authors report that neurons in the brain directly signal satiety (being full, not hungry) and to burn extra calories.

Regulating Energy Balance: The Substrate Strikes Back, Jeffrey S. Flier, Science 12 May 2006: 861-864.
"Hormones and dietary nutrients control appetite and metabolism by acting on the brain, where the signals they elicit promote hunger or satiety. Neurons in the hypothalamus integrate these signals to regulate energy balance."

The main story, Hypothalamic mTOR Signaling Regulates Food Intake, by Daniela Cota et al, Science 12 May 2006: 927-930, states
"Central administration of leucine increases hypothalamic mTOR signaling and decreases food intake and body weight." This strikes Nutriton Investigator as a really big deal.

Here is some background on the amino acid leucine. It is a member of the branched-chain amino acid  family, along with valine and isoleucine. The three branched-chain amino acids constitute approximately 70 percent of the amino acids in the body proteins. As  such, their value in the formation and maintenance of structural and functional  integrity in humans is unmeasured.

During times of starvation, stress, infection, or recovery  from trauma, the body mobilizes leucine as a source for gluconeogenesis (the  synthesis of blood sugar in the liver) to aid in the healing process. It has  recently been suggested that leucine may have beneficial therapeutic effects on  the prevention of protein wasting, as it occurs during starvation,  semi-starvation, trauma, or recovery after surgery. Insulin deficiency is known to result in poor utilization of leucine; therefore, individuals who suffer from glucose intolerance may require higher levels of leucine intake. It has  also been recently suggested that leucine has anabolic effects, thereby  preventing muscle protein breakdown and stimulating muscle protein synthesis.  Therapeutic use of leucine occurs at doses between 500 and 1,000 mg per day.

Foods high in leucine include:
· Cottage cheese (dry) 4,500 mg/cup
· Cottage cheese (crmd) 3,294 mg/cup
· Fish & other seafoods 1,000-10,000 mg/lb
· Meats 2,000 -8,500 mg/lb
· Poultry 3,500-8,500 mg/lb
· Peanuts, roasted w skin 4,500 mg/cup
· Sesame seeds 3,500 mg/cup
· Dry, whole lentils 3,500 mg/cup

Here's another article suggesting leucine may have benefits:
Eggs Get Hype for Helping Older People in Weight Loss and Risk of Vision Loss

Dec. 1, 2004 – Eggs, which not long ago were taking a beating in nutrition circles, are touted today in the Journal of the American College of Nutrition as helping older women in weight loss and reducing the risk of cataract and age-related macular degeneration (AMD).
            Leucine, an essential amino acid found in high quality protein like eggs, potentially provides a weight loss advantage during dieting by helping to reduce loss of lean tissue, promote loss of body fat, and stabilize blood glucose levels.
            The study, which investigated the efficacy of two 1,700-calorie weight loss diets among women aged 45 to 57 years, found that women who ate the higher protein breakfast foods including eggs, low fat dairy and lean meats (containing 10 grams leucine daily) lost slightly more weight, but of the weight lost, nearly twice as much was fat compared to those eating a carbohydrate rich breakfast (containing 5 grams leucine daily).

And here is another story from webmd dating back to February, 2003, titled "Protein diet may prompt Weight Loss" in the Journal of Nutrition, also highlighting the role of leucine. "Though all the women lost about 16 pounds each, those in the higher-protein group lost more body fat and retained more lean muscle than those the high-carb group. "However, when we did a follow-up four months later, we found the higher-protein group continued to lose weight while the high-carb group had plateaued and lost no additional weight," says Layman. The researchers also found that the higher-protein group had lower blood sugar levels, making them less prone to type 2 diabetes."

Leucine references - here are many articles you can read documenting the beneficial effects of leucine

1.            Garlick,            P.J.            The            role            of            leucine            in            the            regulation            of            protein            metabolism.            J Nutr,            2005.            135(6            Suppl):            p.            1553S–6S.
2. Halton TL, Hu FB. The effects of high protein diets on thermogenesis, satiety and weight loss: a critical review.   J Am Coll Nutr            2004;            23:373–85.
3.            Hill            AJ            BJ.            Macronutrients            and            satiety;            the            effects            of            a            high            protein            or            high            carbohydrate            meal            on            subjective            motivation  to eat and food preferences. Nutr Behav            1986;            3:133–144.
4.            Koopman            R,            Wagenmakers            AJ,            Manders            RJ,            et            al.            Combined            ingestion            of            protein            and            free            leucine            with            carbohydrate
             increases            postexercise            muscle            protein            synthesis            in            vivo            in            male            subjects.            Am J Physiol Endocrinol Metab            2005;            288
             E645–53.
5.            Layman            DK.            The            role            of            leucine            in            weight            loss            diets            and            glucose            homeostasis.            J Nutr            2003;            133:261S–267S.
6.            Layman,            D.K.            and            D.A.            Walker,            Potential            importance            of            leucine            in            treatment            of            obesity            and            the            metabolic            syndrome.  J Nutr,            2006;            136(1            Suppl):            p.            319S–23S.
7.            Ludwig            DS,            Majzoub            JA,            Al-Zahrani            A,            Dallal            GE,            Blanco            I,            Roberts            SB.            High            glycemic            index            foods,            overeating,            and            obesity.  Pediatrics            1999;                        103:E26.
8.            Weigle            DS,            Breen            PA,            Matthys            CC,            et            al.            A            high-protein            diet            induces            sustained            reductions            in            appetite,            ad            libitum            caloric
 intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations. Am J Clin Nutr   2005;            82:41–8.

 

 

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