Proteins

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Proteins
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Dietary Sources

• -Animal Products-contain the highest- quality
  proteins.
  
• -Eggs, milk most meat are complete proteins
  that meet all the bodys amino acid requirements
  for tissue maintenance growth.
  
• -Legumes (beans peas), nuts cereals are
  protein rich but their proteins are nutritionally
  incomplete because they are low in one or more of
  the essential amino acids.
• - Leafy green vegetables are well balanced in
  amino acids.
  
• -Vegetarians must be careful when planning diets
  to account for all amino acids to prevent protein
  malnutrition.
  

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Uses in the body

• Proteins are important structural materials of
  the body, including keratin of skin, collagen
  elastin of connective tissue muscle proteins.
  
• Functional proteins such as enzymes, hemoglobin,
  and some hormones regulate an incredible variety
  of body functions

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Cont.

• All or none rule- All amino acids needed to make
  a particular protein must be present in a cell at
  the same time and in sufficient amounts. If one
  is missing, the protein cannot be made
• Adequacy of caloric intake- For optimal protein
  synthesis, the diet must supply sufficient carbs
  or fat for ATP production. When it doesnt
  dietary and tissue proteins are used for energy.

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Cont.

• Nitrogen balance of the body
• Hormonal controls

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Dietary Requirements

• The amount of protein a person needs reflects his
  or her age, size, metabolic rate, and current
  state of nitrogen balance.
  
• Rule of thumb- nutritionists recommend 0.8g per
  kilogram of body weight.
  
• Most Americans eat far more protein than they
  need.

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Excess or Deficits

• Excesses- obesity possibly aggravation of
  chronic disease states.
  
• Deficits- Profound weight loss and tissue
  wasting growth retardation in children anemia
  edema (due to deficits of plasma proteins) During
  pregnancy miscarriage or premature birth.