Nutrition Year 10 Food Technology

What does Protein Do? Function of Proteins Protein has a large number of important functions in the human body. The human body is about 45% protein. Without protein our bodies would be unable to repair, regulate, or protect themselves.

We are Protein!! We are protein...

Functions of Protein . Needed for building and repair of body tissues Needed to make enzymes and hormones. Essential for water balance, nutrient transport and muscle contractions .

Functions of protein Protein is a source of energy ( 1g protein provides 17kj/4kcal) Protein helps keep skin, hair, and nails healthy. Protein, like most other essential nutrients, is absolutely crucial for overall good health.

Functions Protein is essential: as a secondary source of energy if the body receives insufficient energy from carbohydrates and fat sources

Veggies eat proteins extracted from soya beans and fungi Proteins come from mainly foods from animals but there other foods rich in protein which are derived from plants!!

Sources of Protein

Made of amino acids (building blocks of all proteins) Carbon Oxygen Hydrogen Nitrogen

COMPOSITION OF PROTEINS Proteins are made up of complex chains of amino acids. Amino acids can consist of between 50 and tens of thousands of amino acids. 20 different amino acids are required in the body, each with a specific function For healthy growth and repair of the human body, you will need all 20 amino acids

COMPOSITION OF PROTEINS Some amino acids can NOT be made in the body and need to be obtained from the food you eat. These are called ESSENTIAL AMINO ACIDS ( indispensable)

Composition of proteins Amino acids which can be made by the body are called: NON-ESSENTIAL AMINO ACIDS ( dispensable)

Composition of proteins For Adults, 8 amino acids have to be provided in the diet. These include: Lycine Valine Children require 7 amino acids to be provided by the diet. The most important being histidine. Conditionally essential amino acids need to be obtained from food sources at certain life stages because they cannot be produced in sufficient quantities to satisfy the needs of the body

How much protein do we need? The amount of protein needed in the diet depends on the person’s weight, age and health. As a rough guide the RNI ( REFERENCE NUTRIENT INTAKE) for protein is: children 1 t -3 yrs 15g 4-6 yrs 20g 7-10 yrs 28g 11-14 yrs 42g 15-18 yrs 55g Adults 19-50 yrs 55g 50 yrs+ 53g

LOW BIOLOGICAL VALUE FOODS Foods that are deficient in one or more of the ESSENTIAL AMINO ACIDS are said to have: A LOW BIOLOGICAL VALUE (LBV) These are foods originating from plants. For e.g. cereals, nuts seeds, lentils, beans pulses.

HIGH BIOLOGICAL VALUE Foods containing ALL the essential amino acids are said to have: A HIGH BIOLOGICAL VALUE Foods originating from animal sources are said to Are all HBV foods. These include, meat, fish, eggs, cheese & milk

SOYA & QUORN These are the only two non animal derived HBL foods Soya products are derived from soya beans ( Tofu, textured vegetable protein (TVP), soya sauce, tempeh and miso Quorn products are derived from an edible fungus: mycoprotein. Soya and quorn products have been promoted as healthy high protein foods and meat substitutes.

Summary Low Biological Value Foods High Biological Value Foods Contain all essential amino acids Only contain some of the essential amino acids Called high biological value foods. Called low biological value foods. Mostly found in dairy products e.g. meats, fish, poultry, cheese, eggs, yogurt, and milk) Seafood and soya beans are also complete proteins Mostly found in plant foods e.g. legumes, grains (Wheat, Oats, Rice, Barley, Corn), seeds and vegetables.

Estimated average daily requirement – Protein You can calculate the estimated average daily requirement (EAR) for protein using this formula: EAR in g = 0.6 × body mass in kg For example, what is the EAR for a 60 kg person? EAR = 0.6 × 60 = 36 g of protein

Combining proteins By combining foods a complete protein meal can be made and your body receives all nine essential amino acids E.g. Peanut butter on wholemeal bread Beans on toast Tofu-vegetable stir-fry. By combining 2 or more LBV proteins creates complementary proteins To obtain the required balance of amino acids vegetarians need to include a variety of protein sources a combination of plant foods in their daily diet

What happens when you don’t get enough protein Symptoms: Loose weight . Tissues waste away. Ribs become visible. Fat belly because digestion is affected. The body becomes frail and weak. Eyes appear sunken. Brain damage and death

Protein deficiency Symptoms include a badly swollen abdomen Who is at risk Kwashiorkor is a type of protein energy malnutrition Infants and children in underdeveloped countries  Those around the world who live in extreme poverty Causes overpopulation (too many people for the land and resources available)