Functions of protein: 1) body growth (hair fingernails plus toenails), 2) to repair The body recover from injury, give body energy although the body prefers to get most of its energy from carbs, enzymes digest your food
Protein is a macronutrient which is found in animal plus plantfoods
Protein molecules are made up of building blocks called amino acids
Proteins are very large molecules
The body will only use protein for energy if it does not have enough from carbs or fat
Proteins are also needed to make other essential things example hormones to make you grow, enzymes to digest your food, antibodies to help you fight injections
Five protein HBV foods: meat, fish, eggs, milk, yoghurt
5 LBV protein foods: beans, peas, lentils, oats, bread
Protein alternatives: soya, tofu, tempeh, Quorn
Deficiency of protein: children do not grow properly, hair loss, poor skin and nails, infections, poor digestion of food
The body cannot grow without the right amount of protein
The immune system needs protein to stop infections
Excess protein: excess stored as fat, weight gain, puts a strain on the liver + kidneys
excess protein means liver and kidneys have to work hard, puts them under stress which could harm them
Protein a day: 15 year old female: 45g 70 year old man= 53.3g pregnant women aged 29: 51g
Protein is a type of macronutrient. A macronutrient is a type of food that we need lots of in our diet. Foods like eggs, chicken, salmon and milk all contain protein.
Growth - general body growth as well as the growth of specific body parts, like muscles, bones and skin.
Repair - mending organs, muscles and tissues after we get ill or are injured.
Maintenance - producing antibodies to prevent illness and enzymes to help digestion.
Secondary source of energy - if the body doesn't have enough carbohydrates and fats, protein can be used as a reserve energy source.
Protein complementation
Protein complementation is a way of making sure that we get all the essential amino acids we need in our diets. It involves combining various LBV proteins.
E.g. peanut butter and wholegrain bread are both lacking some essential amino acids. But a peanut butter sandwich gives us all the necessary essential amino acids.
HBV proteins store all the essential amino acids that humans need, but LBV proteins don't.
HBV protein plant sources
HBV proteins are also found in some plant-based foods, such as soya beans.
HBV protein animal sources
We get most HBV proteins from animal sources, such as chicken, salmon and milk.
LBV protein sources
LBV proteins are only located in plant-based foods, such as cereals.
Meat and fish are good sources of protein. Vegetarian foods that contain proteins include eggs, green vegetables, chickpeas and potatoes.
Soya beans
HBV source of protein.
Plant-based.
Used to produce soya milk, soy flour and tofu.
Cannot be eaten raw (cooking removes toxic elements).
Mycoprotein
Made by combining a fungus with egg white.
Can make a vegan version of mycoprotein by using potato-starch.
Sold in chunks, fillets or mince form.
Textured vegetable protein (TVP)
Soya flour (ground soya beans) is used to make TVP.
Soya flour can be used in dough. When it's baked, it's texture is like meat. It can be used in chilis and casseroles.
Tofu
Tofu is curdled soya milk.
Water consistency affects the texture.
For example, soft tofu contains lots of water.
Dietary reference values offer rough guidelines for how much protein people should have in their diets. Having too little or too much protein can cause serious health problems.
Dietary reference values
Estimates of the levels of nutrients people need in their diets.
Average male - 55g daily.
Average female - 45g daily.
But these are only estimates and, in reality, needs vary:
Pregnant women - need around 6g more protein to support the baby's growth.
Growing children and adolescents - need more protein than their size and body mass suggest.
Consequences of too much protein
Can strain liver and kidneys (involved in processing proteins).
Consequences of too little protein
Slowed growth.
Poor digestion.
Hair loss.
Malfunctioning immune system (so higher likelihood of catching disease).
Infections, such as:
Oedema (swelling caused by a build-up of fluid).
In extreme circumstances, a nutritional disorder called Kwashiorkor (oedema of the stomach is a symptom).
The average male should have 55g daily and the average female should have 45g daily.
The digestive system would not work properly without enough protein