diet Flashcards
diet
this is a term used to describe the quantity and quality of food eaten.
a ballanced diet
a balanced diet is one that has all necessary nutrients needed to live in sufficient portions to maintain good health.
organic nutrients
these are required in the diet in relatively large amounts. carbohydrates protien lipids vitamins
monosacharide
compounds containing one ring structure are called monosachride eg. glucose and fructose (simple sugars)
disaccharide
two monosacharides can combine to form a disaccharide.
this happens in a condensation reaction as a water molecule is removed
polysaccharide
many rings joined together long chains of simple sugars.
*insoluble and do not have a sweet taste. eg starch ,celulose,glycogen.
protein
made up of long chain of amino acids(and can be arranged in any order)
*a different order results in a different protien
protein uses
used for making new cells,growth and damaged parts of the body.
lipids(fats and oils)
four molecules(three fatty acids and one glycerol) joined together.
- insoluable in water
- secondary source of energy after carbohydrates
- functions as insulation for animals especially in cold areas
vitamins
A,B,C,D,E and K each has its functions
Vitamin A (and its precursor*, beta-carotene)
Needed for vision, healthy skin and mucous membranes, bone and tooth growth, immune system health
Vitamin A from animal sources (retinol): fortified milk, cheese, cream, butter, fortified margarine, eggs, liver
Beta-carotene (from plant sources): Leafy, dark green vegetables; dark orange fruits (apricots, cantaloupe) and vegetables (carrots, winter squash, sweet potatoes, pumpkin)
Vitamin D
Needed for proper absorption of calcium; stored in bones
Egg yolks, liver, fatty fish, fortified milk, fortified margarine. When exposed to sunlight, the skin can make vitamin D.
Vitamin E
Antioxidant; protects cell walls
Polyunsaturated plant oils (soybean, corn, cottonseed, safflower); leafy green vegetables; wheat germ; whole-grain products; liver; egg yolks; nuts and seeds
Vitamin K
Needed for proper blood clotting
Leafy green vegetables such as kale, collard greens, and spinach; green vegetables such as broccoli, Brussels sprouts, and asparagus; also produced in intestinal tract by bacteria
Thiamine (vitamin B1)
Biotin
Part of an enzyme needed for energy metabolism
Widespread in foods; also produced in intestinal tract by bacteria
Part of an enzyme needed for energy metabolism; important to nerve function
Found in all nutritious foods in moderate amounts: pork, whole-grain or enriched breads and cereals, legumes, nuts and seeds
Thiamin (B1)
Thiamin is also known as vitamin B1 and helps to convert glucose into energy and has a role in nerve function.
Good sources of thiamin – include wholemeal cereal grains, seeds (especially sesame seeds), legumes, wheatgerm, nuts, yeast and pork
Riboflavin (B2)
Riboflavin is primarily involved in energy production and helps vision and skin health.
More information about riboflavin includes:
Good sources of riboflavin – include milk, yoghurt, cottage cheese, wholegrain breads and cereals, egg white, leafy green vegetables, meat, yeast, liver and kidney.
Niacin (B3)
Niacin is essential for the body to convert carbohydrates, fat and alcohol into energy. It helps maintain skin health and supports the nervous and digestive systems. Unlike other B-group vitamins, niacin is very heat stable and little is lost in cooking.
Good sources of niacin – include meats, fish, poultry, milk, eggs, wholegrain breads and cereals, nuts, mushrooms and all protein-containing foods.
Pantothenic acid (B5)
Pantothenic acid is needed to metabolise carbohydrates, proteins, fats and alcohol as well as produce red blood cells and steroid hormones.
Good sources of pantothenic acid are widespread and found in a range of foods, but some good sources include liver, meats, milk, kidneys, eggs, yeast, peanuts and legumes.
Vitamin B6 (pyridoxine)
Pyridoxine is needed for protein and carbohydrate metabolism, the formation of red blood cells and certain brain chemicals. It influences brain processes and development, immune function and steroid hormone activity.
Good sources of pyridoxine – include cereal grains and legumes, green and leafy vegetables, fish and shellfish, meat and poultry, nuts, liver and fruit.
Biotin (B7)
Biotin (B7) is needed for energy metabolism, fat synthesis, amino acid metabolism and glycogen synthesis. High biotin intake can contribute to raised blood cholesterol levels.
Good sources of biotin include cauliflower, egg yolks, peanuts, liver, chicken, yeast and mushrooms.
Folic acid (folate or B9)
Folate is needed to form red blood cells, which carry oxygen around the body. It helps the development of the foetal nervous system, as well as DNA synthesis and cell growth.
Good sources of folate – these include green leafy vegetables, legumes, seeds, liver, poultry, eggs, cereals and citrus fruits.
Vitamin B12 (cyanocobalamin)
Vitamin B12 helps to produce and maintain the myelin surrounding nerve cells, mental ability, red blood cell formation and the breaking down of some fatty acids and amino acids to produce energy. Vitamin B12 has a close relationship with folate, as both depend on the other to work properly.
Good sources of B12 include liver, meat, milk, cheese and eggs, almost anything of animal origin.
Thiamin deficiency
is generally found in countries where the dietary staple is white rice. Deficiencies in the Western world are generally caused by excessive alcohol intake and/or a very poor diet. Symptoms include confusion, irritability, poor arm or leg (or both) coordination, lethargy, fatigue and muscle weakness.
Riboflavin deficiency (ariboflavinosis)
is rare and is usually seen along with other B-group vitamin deficiencies. People at risk include those who consume excessive amounts of alcohol and those who do not consume milk or milk products. Symptoms include an inflamed tongue (painful, smooth, purple-red tongue), cracks and redness in the tongue and corners of the mouth, anxiety, inflamed eyelids and sensitivity to light, hair loss, reddening of the cornea and skin rash.
Excessive intake of B3
large doses of niacin produce a drug-like effect on the nervous system and on blood fats. While favourable changes in blood fats are seen, side effects include flushing, itching, nausea and potential liver damage.
Niacin deficiency (pellagra)
people who drink excessive amounts of alcohol or live on a diet almost exclusively based on corn are at risk of pellagra. Others causes are associated with digestive problems where the body does not absorb niacin efficiently. The main symptoms of pellagra are commonly referred to as the three Ds – dementia, diarrhoea and dermatitis. Other symptoms include an inflamed and swollen tongue, irritability, loss of appetite, mental confusion, weakness and dizziness.
Pantothenic acid deficiency
is extremely rare. Symptoms include loss of appetite, fatigue and insomnia, constipation, vomiting and intestinal distress.
Excessive intake of pyridoxine
mostly due to supplementation, can lead to harmful levels in the body that can damage nerves. Symptoms include walking difficulties and numbness in the hands and feet. Large doses of B6 taken over a long period can lead to irreversible nerve damage.
Pyridoxine deficiency
people who drink excessive alcohol, women (especially those on the contraceptive pill), the elderly and people with thyroid disease are at particular risk of deficiency. Symptoms include insomnia, depression, anaemia, smooth tongue and cracked corners of the mouth, irritability, muscle twitching, convulsions, confusion and dermatitis
Biotin deficiency
is very rare because biotin is widely distributed in foods and is only required in small amounts. Over-consumption of raw egg whites over periods of several months by bodybuilders, for example, can induce deficiency because a protein in the egg white inhibits biotin absorption. Symptoms include pale or grey skin, cracked sore tongue, depression, hallucinations, abnormal heart actions, loss of appetite, nausea, dry skin and scaly dermatitis, hair loss, muscle pain, and weakness and fatigue.
Excessive intake
folate is generally considered non-toxic, although excessive intakes above 1,000 mg per day over a period of time can lead to malaise, irritability and intestinal dysfunction. The main risk with excessive folate intake is that it can mask a vitamin B12 deficiency, so it is best to consume these two vitamins within the recommended amounts.
Folate deficiency
the symptoms include weight loss, tiredness, fatigue and weakness, folate-deficiency anaemia (megaloblastic anaemia) and (during pregnancy) an increased risk of a neural tube defects such as spina bifida for the baby.
Vitamin B12 deficiency
is most commonly found in the elderly, vegans (vitamin B12 is only found in foods from animal sources) and breastfed babies of vegan mothers. Symptoms include tiredness and fatigue, lack of appetite, weight loss, heart palpitations, shortness of breath, vision loss, smooth tongue and mental problems, such as depression and memory loss.
A lack of vitamin D
can lead to rickets in children and weakness, aches,and pains in adults where bones don’t have enough calcium. This is called osteomalacia.
Excessive amounts of vitamin C
You’d have to take a lot of vitamin C from supplements to overdose, but very high levels over long periods can lead to kidney stones.
Excessive intake of salt
Having too much salt is linked to an increase in blood pressure (hypertension), which raises your risk of a stroke and heart attack
Excessive intake of calcium
Although calcium toxicity is rare, symptoms may include fatigue, depression, muscle weakness, kidney stones, constipation, and spondylitis (rigidity and inflammation of the spine).
Phosphorus
Phosphorus is a mineral that helps to build strong bones and teeth,also helping to release energy from food.
Magnesium
Magnesium helps turn the food we eat into energy and helps to make sure the parathyroid glands, which produce hormones that are important for bone health, work normally.
Taking high doses of magnesium for a short time can cause diarrhea, nausea, vomiting, and abdominal cramping.
Iron
Iron is an essential mineral with several important roles in the body. For example, it helps to make red blood cells which carry oxygen around the body.
A lack of iron can cause iron deficiency anemia and is not uncommon even in the West.
Zinc
Zinc helps to make new cells and enzymes, helps us process carbohydrates, fatand protein in food, and helps with the healing of wounds.
Taking high doses of zinc reduces the amount of copper the body can absorb. This can lead to anemia and weakening of the bones.
Manganese
Manganese is a trace element that helps make and activate some of the enzymes in the body.
Taking high supplemental doses of manganese for long periods of time might cause muscle pain, nerve damage,and neurological symptoms,
Selenium
Selenium is a trace element that plays an important role in our immune system’s function and in reproduction. It is also a potent antioxidant and helps to prevent damage to cells and tissues.
Chromium
Chromium is a trace element thought to influence how the hormone insulin behaves in the body. This means chromium may affect the amount of energy we get from food.
Iodine
Iodine is involved in the synthesis of thyroid hormones. These hormones help to keep cells and the metabolic rate healthy.
Taking high doses of iodine for long periods of time could change the way your thyroid gland works. This can lead to a wide range of different symptoms, such as weight gain.