Topic 4 Proteins

  • Protein is needed for movement, structural support, and enzyme-drive chemical reactions
  • Proteins are made up of amino acids
  • The human body cannot synthesize amino acids and they must be therefore consumed

Amino Acids

  • There are 9 amino acids which are indispensable (meaning, you can’t live without them!)

Essential Amino Acids:

  • Histidine
  • Phenylalanine
  • Methionine
  • Valine
  • Lysine
  • Leucine
  • Isoleucine
  • Threonine
  • Tryptophan


How much protein should I be eating?

  • Quality Matters
    • High-quality complete proteins contain sufficient amounts of all nine essential amino acids
    • Lower quality incomplete proteins, with insufficient amounts of at least some of the essential amino acids
  • It depends on weight
    • Multiply one’s weight by 0.8 and convert that number to grams
    • An average man weighing 80 kilos needs a little more than 64 grams

Protein Quality

  • Incomplete proteins lack at least one amino acid
  • Pair incomplete proteins with other incomplete proteins to create complementary food options with all amino acids!
  • Tips for complementary foods:
    • Combine legumes with grains / nuts / seeds / corn
    • Combine vegetables with grain / nuts /seeds

Complete Proteins

  • Most animal sources and products (milk, cheese, eggs, poultry, fish)
  • Soy and its products (soybeans, tofu, soy milk)
  • Quinoa


Incomplete Proteins

  • Most plant-based foods (grains, vegetables, fruits, legumes, nuts, seeds)
Foods Deficient in which amino acid
Methionine and Tryptophan
Threonine, Lysine, and Isoleucine
Nuts and seeds
Lysine and Isoleucine
Tryptophan, Lysine

Complementary Meal Examples