Showing posts with label protein. Show all posts
Showing posts with label protein. Show all posts

Daily protein requirement

Mar 2014   › › › Daily protein requirements
Protein requirement for the human body quite relative and variable controlled by several biological processes. Daily protein necessity depends upon an individual's gender, age, height and weight.
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Relative amounts of other macronutrients like carbohydrates and fats in the diet also alters the body's demands for proteins. The level of physical activity of a person and his lifestyle also have an effect over his necessities of all the macronutrients.

Daily protein requirement and the spectrum of amino acids

The physical and chemical composition as well as the nutritive value of proteins have high degree of variances. Generally the nutritive value is measured analytically in terms of nitrogen it is contributing. There are diverse types of proteins formed from different combinations of amino acids and their sequences in the molecules. They contribute differently to meet the daily requirement of the body for growth, maintenance and repair.

Two major factors are to be considered while assessing the quality of this macronutrient. Digestibility is an important factor as some molecules of the nutrient may not be easily digestible. The digestibility has a direct bearing on the daily requirement. Nearly 20-25 percent of the daily nitrogen consumption is excreted in feces. This is partially due to the physical and chemical composition of the molecule which renders it resistant to breakdown by digestive enzymes for absorption. Some nitrogen is also lost on a daily basis in the form of secretions in the gastrointestinal tract.

  • Calcium supplements
    • The second factor is the amino acid composition. Protein has to be broken down to the constituent amino acids for absorption by the body to meet its daily requirements. The human body can synthesize several amino acids. However, it cannot synthesize certain amino acids which known as essential amino acids.

    These essential amino acids are our daily requirements and our diet must contain them. The deficiency of these amino acids can affect the biological processes such as protein synthesis and the related cellular metabolic activities. A paradox situation arises in our diet wherein the protein content of a particular food is very rich but lacking in some essential amino acids makes it of lesser food value.

    Protein requirements for protein turnover

    In protein turnover, these macronutrients are being continuously broken down and resynthesized in our body. It is estimated that in an adult more than 250 g of this macronutrient is synthesized and broken down daily. In the infants protein turnover is high whereas in elderly people it is less.
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    • The intestine and liver are believed to contribute to more than 50% of the turnover. As the essential amino acids are also lost in the turnover daily requirements arise to make good the loss.

    Protein requirements for energy

    When there is energy restriction due to malnutrition or other factors this macronutrient contributes significantly to the energy by its oxidation. However this process leads to huge loss of protein from the body. This oxidation is also found to be at a high rate in septic or traumatized individuals. It is recommended that "adults should get 45 percent to 65 percent of their calories from carbohydrates, 20 percent to 35 percent from fat, and 10 to 35 percent from protein. Acceptable ranges for children are similar to those for adults, except that infants and younger children have necessity for a slightly higher proportion of fat (25-40 percent)" (Food and Nutrition Board).

    Given below is the abstract of the Recommended Dietary Allowances of protein for various age groups by Institute of Medicine's Food and Nutrition Board.

    Adequate Intake for Infants: 0 Through 6 Months
    0–6 months - 1.52 g/kg/daily

    RDA for Older Infants:
    7–12 months 1.2 g/kg/daily

    RDA for children Ages 1 - 13 Years
    1–3 years 1.05 g/kg/daily
    4–8 years 0.95 g/kg/d
    9–13 years 0.95 g/kg/d

    Adolescents Ages 14 years - 18 Years:
    RDA for Boys and girls 14–18 years 0. 85 g/kg/daily

    Adults Ages: 19+:
    RDA for Men and women 0.80 g/kg/d

    RDA for Pregnancy
    In pregnant women additional requirements arise in the last two trimesters of about 25 g/d over and above the pre-pregnancy requirements.
    All age groups 1.1 g/kg/d or +25 g/d of additional necessities

    RDA for Lactation:
    All age groups 1.3 g/kg/d or +25 g/d of additional requirements

    Individuals on active sports and muscle building will have higher protein requirements.
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    Daily protein requirements.
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    Protein deficiency diseases

    Jan 2014  › › Protein deficiency diseases
    Proteins are the major constituents of the body and are required for most of the vital body functions. Deficiency of proteins can cause many health issues and also diseases like kwashiorkor and marasmus.
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    As there is continuous proteins building as well as degradation in human body for its normal functions, their regular optimal intake is very essential for keeping good health. If our body does not receive enough of it from the diet, the protein in the muscles and tissues in the body is depleted.

    Protein deficiency diseases occur in developing countries due to poverty as well as lack of knowledge about their nutritional requirements. In regions devastated by strife, wars, drought, famine, floods and blights, food becomes scarce and protein inadequacy and connected pathological conditions become common.

    In developed nations, though protein inadequacy in nutrition is very rare, it does occur in neglected children and seniors. In patients with chronic debility and cachexia requiring prolonged hospitalization, there is maldigestion, malabsorption and inefficient utilization of nutrients. In such cases there can be shortcoming in amino acids intake.

    Unique protein deficiency diseases

    Protein C deficiency is an inherited debility affecting the production of body's natural anticoagulant. It causes abnormal blood clotting (thrombosis) specially in veins.

    Protein S deficiency also affects the production of natural anticoagulant. However the cause can either be genetic or acquired through a shortfall in vitamin K.

    Alpha-1 antitrypsin deficiency, one type of protein inadequacy syndrome, causes difficulty in breathing, wheezing, vision problems and weakness.

    Mitochondrial trifunctional protein deficiency causes low blood sugar, weakness, cardiac and hepatic problems, wasting of muscles and difficulty in feeding.

    Protein deficiency diseases of specific amino acids

    Proteins are made up of amino acids. 22 amino acids are found to be present in human tissues. Many of the amino acids can be synthesized by our body. However nine of them are very essential as our body cannot synthesize and we have to get them through our food sources. The chronic inadequacy of any of these essential amino acids can also cause specific abnormal and harmful functioning. Even the non essential amino acids are also required to be supplemented to ensure an optimal available quantity for building proteins.

    Some of these essential amino acids and the deleterious effects on health  due to their inadequacy in the food composition is briefly discussed here.

    Histidine

    A shortfall of L-histidine in the food source can lead to symptoms like anemia, lowering of  histamine production, lowered zinc absorption, and lowered immune responses.

    Isoleucine

    A dearth of Isoleucine in the protein source can lead to symptoms like headaches, giddiness, weakness, depression, confusion and irritability.

    Leucine

    Undersupply of Leucine in the diet shows symptoms similar to hypoglycaemia. Symptoms include headache, giddiness, weakness, lack of mental stability, disorientation, irritability and depression.

    Lysine

    Want of Leucine in dietary protein shows symptoms like irritability, dizziness, fatigue, anemia, mood swing, hair loss and stunted growth.

    Methionine

    Scarcity of Methionine in diet can lead to reduced synthesis of cysteine, which protects liver cells from destruction. Increased lipid peroxidation, depression, elevated risk of atherosclerosis are some of the effects of dearth in the biological availability of methionine.

    Phenylalanine

    Manifestations of phenylalanine inadequacy include confusion, lethargy, lack of energy, fluid retention, depression, skin lesions, decreased alertness, liver damage, memory problems, slow growth and lack of appetite.

    Threonine

    Symptoms of threonine inadequacy include irritability, mood swing, impulsiveness and memory problems. Its inadequacy appears to affect the brain functions.

    Tryptophan

    Dietary dearth of tryptophan may lead to low levels of serotonin. Low serotonin levels are associated with depression, anxiety, panic, irritability, mood change, impatience, impulsiveness, inability to concentrate, increase in weight, food cravings, aggressiveness and insomnia.

    Valine

    A shortfall of valine in dietary protein may affect the myelin covering of the nerves. The inability to metabolise leucine, isoleucine, and valine causes Maple syrup urine disease (MSUD). The urine of the persons affected by this disease smells like maple syrup.
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    Protein energy malnutrition in children

    March 2013
    Home > Nutritional deficiency diseases > Protein energy malnutrition in children
    What is protein energy malnutrition?
    Also known as protein-calorie malnutrition, this type of malnutrition results from the acute insufficiency of both dietary energy and proteins.
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    Considering the time and origin its cause can be primarily due to lack of amino acids and energy nutrients in the diet or secondarily due to debilitating health conditions. In children losing up to 10% of body weight is considered as mild, whereas losing 10-20% is moderate and above 20% is severe malnutrition.

    Causes of protein energy malnutrition in children

    The primary malnutrition develops in children when their intake of proteins and energy sources is grossly insufficient to support their metabolic needs. This type of malnutrition is seen mostly in developing countries and also in regions ravaged by wars, famines and natural calamities.

    The secondary type of malnutrition in children is prevalent even in developed countries. It is usually concurrent with major health problems like AIDS, chronic diarrhea, cancer, chronic kidney failure, chronic obstructive pulmonary disease (COPD), liver cirrhosis, Crohn disease and ulcerative colitis. In these debilitating illnesses, the body's ability to digest, absorb or use the nutrients is impaired. Severe malnutrition may occur in persons on long-term hemodialysis and in those affected by acute illness, severe burns, trauma, or sepsis.

    When malnutrition syndrome reaches an advanced disease stage, depending upon the type of deficiency, it is variously named as Kwashiorkor or marasmus.

    Kwashiorkor

    Kwashiorkor
    1.protein-energy malnutrition
    Kwashiorkor affected child
    This is an advanced disease stage of malnutrition wherein there is acute protein deficiency. Symptoms of kwashiorkor include, protruding belly, liver enlargement and ascites, edema, dry and peeling skin, changes in skin pigment, loss of muscle mass, diarrhea, anemia, change in hair color and texture, apathy, irritability, dermatitis and severe infections. Delay in treatment can lead to permanent mental and physical disability, coma, shock and death. This condition is seen in children feeding on highly amino acid deficit diet after stoppage of breast feeding.

    Marasmus

    Unlike kwashiorkor, in marasmus there is severe protein and also calorie/energy deficiency. There is no edema. Marasmus is characterized by wasted muscles and tissues. Marasmus may appear in children who have very little to eat after stoppage of breast feeding. The symptoms include profound weakness, emaciation, baggy, wrinkled skin, lack of energy, extremely thin arms and legs, weakened immune system, low body temperature and mental and behavioral retardation.
    marasmus
    2.protein-energy malnutrition
    marasmus affected child
    In children with marasmus if severe infections and complications occur, edema may be caused and the malnutrition syndrome is now termed as marasmic kwashiorkor.

    Like children, elderly people are also dependent on others for getting the right type of nutrition and in addition their digestive and absorptive capacities are reduced. Like children, they are also at the high risk of developing the secondary malnutrition.

    Diagnosis

    Malnutrition can be recognized by correlating the symptoms with the visual observation and physical examination of body fat, eating habits, appetite, weight loss, edema and muscle strength. The history of general illnesses, diarrhea and gastrointestinal ailments can give an idea on the patients nutritional status. Blood and urine analysis will further help in the diagnosis.

    Treatment

    Immediate step in the treatment of malnutrition is correcting fluid and electrolyte imbalances. Antibiotics are given for treating infections. Gradually essential nutrients are replenished, first the carbohydrates and then the amino acids and micronutrients. Physiotherapy is given to make the patient gain the muscle strength. Once the affected children are free from complications energy dense dietary formulas are used to restore normal weight for the height. If the treatment is delayed, protein energy malnutrition can leave lasting effects on physical and mental health of children and they may not reach their full growth potential.
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    Related topics:
    Carbohydrate Deficiency Diseases.
    Protein deficiency diseases.
    Protein-energy malnutrition (PEM).
    Vitamin deficiency diseases.
    Fat deficiency diseases.
    Mineral deficiency diseases.
    Image 1 source: http://phil.cdc.gov/
    Content Providers: CDC/ Dr. Lyle Conrad
    License: Public domain
    Image 2 source: http://phil.cdc.gov/
    Content Providers: CDC/ Don Eddins
    License: Public domain

    Reference: Alderman H, Shekar M. Nutrition, food security, and health.In: Kliegman RM,Behrman RE, Jenson HB, Stanton BF, eds.Nelson Textbook of Pediatrics.19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 43.
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    High protein food sources

    › High Protein food sources

    Proteins in cereal food sources
    Corn and rice, the staple food sources of the third world are poor in proteins and are leading to obesity of the populations due to high carbohydrate content of these cereals.
    Protein food sourcesValue per 100g
    UnitProteinfatsCarbohydrateEnergy
    Wheat flour, whole grain gram
    13.70
    		 1.87
    72.57
    		339 kcal
    Rice, white,medium, raw gram
    6.61
    		 0.58
    79.34
    		360 kcal
    Corn flour whole graingram
    6.93
    		 3.86
    76.85
    		361 kcal
    Barley flour gram
    10.50
    		 1.60
    74.52
    		345 kcal
    oatsgram
    16.89
    		 6.90
    66.27
    		389 kcal
    Finger millet (ragi) gram
    7.3
    		 1.3
    72.00
    		328 kcal
    Millet, raw gram
    11.02
    		 4.22
    72.85
    		378 kcal
    Sorghum grams
    11.30
    		 3.30
    74.63
    		339 kcal
    Rye flour, medium gram
    10.88
    		 1.52
    75.43
    		349 kcal
    Triticale flour, whole-grain gram
    13.18
    		 1.81
    73.14
    		338 kcal
    Teff, uncooked gram
    13.30
    		 2.38
    73.13
    		367 kcal
    Buckwheatgrams
    13.25
    		 3.40
    71.50
    		343 kcal
    Quinoa, uncookedgram
    14.12
    		 6.07
    64.16
    		368 kcal

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    High protein vegetarian food sources
    High Protein food sourcesValue per 100g
    UnitProteinfatsCarbohydrateEnergy
    Soy flour, defatted sourcesgram
    47.01
    		 1.22
    38.37
    		330 kcal
    Soy meal, defatted, raw gram
    49.20
    		 2.39
    35.89
    		337 kcal
    Soybeans, mature seeds boiled gram
    16.64
    		 8.97
    9.93
    		173 kcal
    Soybeans, green, boiled gram
    12.35
    		 6.40
    11.05
    		141 kcal
    Soy milk, originalgram
    3.27
    		 1.75
    6.28
    		54.5 kcal
    Tofu, raw gram
    8.08
    		 4.78
    1.88
    		76.5 kcal
    Soy protein isolate gram
    80.69
    		 3.39
    7.36
    		338 kcal
    Cashew dry roastedgram
    15.31
    		 46.35
    32.69
    		574 kcal
    almonds gram
    21.22
    		 49.42
    21.67
    		575 kcal
    Peanuts, all types, raw gram
    25.80
    		 49.24
    16.13
    		567 kcal
    Peanut flour, defatted gram
    52.20
    		 0.55
    34.70
    		327 kcal
    Peanut butter, chunk gram
    24.06
    		 49.94
    21.57
    		589 kcal
    pumpkin seed kernels,driedgram
    30.23
    		 49.05
    10.71
    		559 kcal
    Lima beans, mature seeds, raw gram
    21.46
    		 0.69
    63.38
    		338 kcal
    Kidney beans mature raw seedsgram
    23.58
    		 0.83
    60.01
    		333 kcal
    Peas, green, raw gram
    5.42
    		 0.40
    14.45
    		81.5 kcal
    Peas, split, mature seeds, raw gram
    24.55
    		 1.16
    60.37
    		341 kcal
    Chickpeas (garbanzo beans, Bengal gram), mature seedsgram
    19.30
    		 6.04
    60.64
    		364 kcal
    Yeast extract spread gram
    27.80
    		 0.00
    11.80
    		158 kcal
    Spirulina, driedgram
    57.47
    		 7.72
    23.90
    		290 kcal
    High protein food sources of animal origin
    High Protein food sourcesValue per 100g of food
    UnitProteinfatsCarbohydrateEnergy
    Milk, whole, 3.25% milk fatgram
    3.15
    		 3.27
    4.78
    		61.5 kcal
    Yogurt, plain, low fat gram
    5.25
    		 1.55
    7.04
    		63.5 kcal
    Cheese, cheddargram
    24.90
    		 33.14
    1.28
    		403 kcal
    Cheese, cottage, low fat gram
    12.39
    		 1.02
    2.72
    		72.5 kcal
    Egg, whole, raw, fresh gram
    12.57
    		 9.94
    0.78
    		143 kcal
    Chicken, breast, meatgram
    21.23
    		 2.59
    0.00
    		114 kcal
    Turkey breast meat gram
    17.07
    		 1.66
    4.21
    		104 kcal
    Fish, cod, raw gram
    17.81
    		 0.67
    0.00
    		82.5 kcal
    Fish, tuna, fresh, skipjack, raw gram
    22.00
    		 1.01
    0.00
    		103 kcal
    Fish, tuna, white, canned, solid gram
    23.62
    		 2.97
    0.00
    		128 kcal
    Lamb meat raw gram
    20.0
    		 5.0
    0.00
    		135 kcal
    Beef, Center Cut Steakgram
    20.67
    		 5.88
    0.00
    		141 kcal
    compiled from USDA database
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