Food Nutrition and Health Flashcards
What is protein and what is its specific function in the body?
**Protein is formed from chains of simpler units called amino acids.
**
* Eight amino acids need to be provided by the diet and are called essential amino acids.
* Children require two additional amino acids.
* Protein is used for specific functions in the body: growth, repair, maintenance, and as a secondary energy source
Name animal and plants sources of protein.
Animal sources - meat, fish, poultry, milk, eggs, cheese, insects.
Plant sources - soya, nuts, seeds, pulses (e.g. lentils), mycoprotein (Quorn), TVP (Texturised Vegetable Protein).
What is the biological value of proteins?
**The biological value of protein means the amount of essential amino acids present.
- Animal protein sources contain all the essential amino acids required by the body; they are of High Biological Value (HBV).
- Mycoprotein (Quorn) and Texturised Vegetable Protein (TVP) are of HBV too.
- Proteins from plant sources are of Low Biological Value (LBV) and lack some essential amino acids.
- The exception is soya, which is a plant protein of HBV.
What is protein complementation and who is it important for?
Proteins of LBV can be eaten together to provide all the essential amino acids, for example, beans on toast.
* This is protein complementation.
* Protein complementation is important for vegetarians and vegans.
What happens if someone has too much protein or too little?
- Excess protein in the diet is used as energy.
- Protein deficiencies are rare but in developing countries kwashiorkor is a severe form of protein malnutrition.
What groups need more protein then others?
- Babies and children for growth
- adolescents - for growth spurts
- pregnant women - for the growing baby nursing
- mothers - for lactation (milk production).
What is fat?
- Fat is a macronutrient.
- It can be solid or liquid.
- Fat is made up of fatty acids and glycerol. bydod Fatty acids can be described as saturated fats or unsaturated fats.
- The structure of fatty acids influences their effect on our health.
- The characteristics of fatty acids influence cooking choice.
What is the functions of fat in the diet?
- Fat provides concentrated energy.
- Fat is a source of fat-soluble vitamins A, D, E and K.
- Fat provides protection for the major organs in the body.
- Fat is a component of hormones.
Give some sources of fat in the diet (unsaturated and saturated)
**Saturated fats: **
* Saturated fats can increase the cholesterol level in the blood.
* Too much bad cholesterol can lead to health problems.
* Sources of cholesterol include butter, ghee, lard, cream, hard cheese, meat pies, coconut oil and palm oil.
Unsaturated fats:
* Unsaturated fats can help reduce cholesterol in the blood.
* Sources include: oily fish, nuts, seeds, avocados, vegetable oils, soya beans, and some functional foods, such as cholesterol-lowering spreads.
* Functional foods are foods specially developed to improve health.
What are hydrogenated fats and trans fat?
- Making solid fat from a liquid oil is called hydrogenation.
- Trans fats can be formed when oil goes through the process of hydrogenation to form a solid. This process occurs as the molecules flip and rotate.
What can happen if someone has too much or two little ft in their diet?
- Fat is only needed in small amounts and excess fat in the diet can lead to weight gain.
- Excess saturated fat raises blood cholesterol levels.
- Trans fats have been linked to health problems including heart disease and some cancers.
- Fat deficiency in babies and children could affect normal growth.
- Fat deficiency could result in a poor supply of fat-soluble vitamins.
What is a carbohydrate?
- The body’s cells require a constant supply of glucose, which is used as fuel to provide energy.
- Sugars and starches are types of carbohydrate.
- Dietary fibre is also a type of carbohydrate but it cannot be forb digested to provide energy.
- Carbohydrates are produced mainly by plants during the process of photosynthesis.
- Carbohydrates can be classified according to their structure: monosaccharides, disaccharides, polysaccharides.
What are monosaccharides and give two examples of them?
Monosaccharides are the simplest form of carbohydrate structure.
They include:
Glucose - all other carbohydrate is converted into this in the body.
Galactose - found in the milk of mammals. Fructose - found in fruit.
What are disaccharides and give three examples of them?
Disaccharides are more complex sugars that are formed when two monosaccharides join together.
They include:
Sucrose - 1 unit of I glucose + 1 unit of fructose
Maltose -2 units of glucose linked
Lactose - 1 unit of glucose + 1 unit galactose
What are polysaccharides and give six examples of them?
Polysaccharides are made up of many monosaccharides units joined together.
They include:
Starch - units formed together
Glycogen - formed after digestion.
Dietary fibre
Dextrin - toasted crust on bread; sugars caramelise on the surface.
Cellulose-formed by plants from glucose.
Pectin - found in fruit, forms a gel on cooking.
What are the functions and sources of carbohydrates?
- Sugars are digested quickly in the body, providing instant energy.
- Starches have to be digested into sugars before absorption - this is slow energy release.
- Eating starchy foods rather than sugary foods is the healthier way to provide the body with energy. Starch (a polysaccharide) is found in bread, pasta, rice, breakfast cereals and potatoes.
- Sugars are found in a variety of sources including table sugar (sucrose), honey and jam, fruit juice, sweets and chocolate, frui and vegetables.
What happens if you have too much or too little carbohydrates?
- Excess carbohydrate is converted to fat and is stored under the skin; this is the main cause of obesity
- Excess sugar in the diet is linked to dental decay.
- There is evidence to suggest that the rise in Type 2 diabetes is linked to diets high in sugar.
- If insufficient carbohydrate is eaten, the body will firstly start to use protein and fat as an energy source.
What are the functions and sources of dietary fibre?
- Dietary fibre makes food matter passing through the intestines soft and bulky.
- Dietary fibre can be found in wholemeal bread, wholegrain breakfast cereals (e.g. bran flakes, shredded wheat, porridge oats) wholemeal pasta and wholemeal flour; fruit and vegetables; potato skins; dried fruit, nuts and seeds, beans, peas and lentils.
- Adults should consume at least 18 g of fibre per day.
- Young children must gradually add high fibre foods to their diets.
Fibre deficiency can lead to:
* Constipation - this is when faeces become difficult to expel from the body because they are hard and small.
* Diverticular disease - pouches form in the intestines, which become infected with bacteria. A low-fibre diet can be linked to cancer, particularly bowel cancer.
What is the function of Vitamin A (Retinol, Beta carotene)?
- Normal iron metabolism.
- Maintenance of normal vision.
- Maintenance of skin and the mucus membranes.
- Essential for maintaining healthy immune function.
What are sources of Vitamin A?
Animal sources - liver and whole milk ( retinol)
Plant sources - green leafy vegetables, carrots and orange-coloured fruits (carotenoids)
Margarine which is fortified by law.
What happens if you have too little or too much Vitamin A?
- Excess can be toxic causing liver and bone damage.
- Excess retinol can lead to birth defects.
- Deficiency can cause night blindness.
What are the functions of Vitamin D (Chlolecalciferol) in the body?
- Absorption and use of calcium and phosphorus.
- Maintenance and strength bones and teeth.
What are sources of Vitamin D?
Dietary sources - oily, fish, meat, eggs and fortified breakfast cereals and margarines (vitamin D added by law).
Sunlight on the skin.
What happens if someone has too little vitamin D?
- Bones that become weak and bend.
- Rickets in children.
- Osteomalacia in adults.
- Weak teeth.
What are the functions of Vitamin E (Tocopherol) in the body?
- Antioxidant that helps protect cell membranes.
- Maintains healthy skin and eyes.
What are sources of vitamin E and deficiencies?
- Polyunsaturated fats, e.g sunflower oils.
- Nuts, seeds and wheatgerm.
- Deficiency is very rare.
What are the functions of Vitamin K (Phytomenadione) in the body?
What are sources of vitamin K?
What is a deficiency/ excess of vitamin K?
- Normal blood clotting
- Green leafy vegetables, cheese, bacon and liver.
- A deficiency is very rare.
- Newborn babies are given a does of Vitamin K.
