What is ‘Protein Quality’?
Quality of protein is determined by: digestibility of a protein, types of AA, and proportion of AA.
What is a ‘good quality’ protein?
- Well (completely) digested: animal pro (90-99%), plant pro (70-90%)
- Contains all essential AA in properties similar to that required by the body.
Protein from foods of animal origin.
complete pro sources.
Eggs, dairy, fish, poultry, ‘meat’
Protein from foods of plant origin
low in at least 1 essential AA
legumes
Protein Recommendations (DRI)
DRI- 10-35% Kcal
RDA values: Adults 0.8 g/kg/day
infants need the most
Do athletes need more protein?
yes
Protein Requirements for Athletes
Non-athlete- 0.8
Endurance athlete- 1.2-1.4
Power athlete (hockey) 1.2-1.7
Is too much protein ‘bad’?
- Increased Kcal intake—> overweight
- High pro foods also increase in fat
- Ca loss in urine increases (bone health)
- Overworked liver and kidney
- Cancer
- Excess protein: impacts on gut microbiome
What is protein?
- Component of every living cell.
- Made up of amino acids (20 AA and 9 are essential)
- Every AA contains N (proteins are 16% N, by weight)
How many peptide bonds in a tripeptide?
two
What foods provide most of our protein?
Cruciferous vegetables: higher protein than other vegetables.
Grain products
Milk products
Meat
Alternatives
Why do we need protein?
Regulating Body process: some hormones (insulin), enzymes (trypsin, lipase, amylase), neurotransmitters (serotonin).
Growth and repair of tissues: muscle protein, normal turnover (breakdown and replacement of all body tissues/organs)
Immune defence: antibodies to fight invading microbes.
Transportation
Other
Energy
