Chapter 4 Flashcards
What are nutrients?
Nutrients are chemical substances that make up food. When digested, they allow the body to function properly
What is elemental composition?
Elements are individual chemicals. The composition of something is the elements that it is made up of. For example; protein is made up of the elements Carbon (C) Hydrogen (H) Oxygen (O) and nitrogen (N)
What is classification?
This is a way of grouping similar things together. For example: proteins are classified as high biological value proteins or low biological value proteins
What is a source
This is a food or something else that provides nutrients to the body. For example, milk is a source of calcium and sunlight is a source of vitamin D
What is reference intake?
This is the average daily intake of a nutrient that is needed to meet the nutritional requirements of the majority of people in a specific age or gender group. For example; teenage girls have an RI of 15 mg of iron per day
What are functions?
These are the jobs a nutrient carries out in the body. For example; carbohydrates provide the body with heat and energy
What are deficiency diseases?
These are diseases that occur when the body is lacking a particular nutrient over a period of time. For example: scurvy is a disease resulting from a lack of Vitamin C
What are the nutrients?
Food has six constituents. Five are nutrients. The sixth is water, which while not a nutrient is vital for the body to function properly
1. Protein
2. Fat
3. Carbohydrates
4. Minerals
5. Vitamins
6. Water
What are constituents?
Constituents are the parts of something that come together to form the whole thing
What is food?
Food is any solid or liquid that provides the body with nutrients. Nutrition is the study of food, the nutrients it contains and how they are used by the body.
According to the world health organisation (WHO) ‘good nutrition- an adequate, well balanced diet combined with regular physical activity- is a cornerstone of good health’
What is the classification of nutrients?
Nutrients are classified into two groups:
1. Macronutrients: These nutrients are needed in large amounts and must be digested to be used by the body. The macronutrients are protein, fat and carbohydrates
2. Micronutrients: these nutrients are needed in small amounts and do not need to be digested. The micronutrients are mineral and vitamins
What is the composition of protein?
Protein is made up of four elements.
1. Carbon
2. Hydrogen
3. Oxygen
4. Nitrogen
Protein is the only nutrient that contains nitrogen (N). This element is needed for the growth and repair of every cell in the body
Protein is made up of a chain of smaller units called amino acids. Amino acids are linked together by peptide links.
Enzymes are substances that help chemical reactions. During digestion, enzymes break down amino acids
What is the classification of protein?
There are two types of protein:
1. High biological Value (HBV) proteins; these are proteins that contain all or most of the essential amino acids needed by the body. Essential amino acids are those the body cannot make itself, so they must come from food. Most HBV proteins are found in animal sources eg: meat
2. Low biological Value (LBV) proteins: these are proteins that do not contain many essential Amino acids and usually come from plant sources eg: cereals
What are the HBV Protein foods (animal origin and meat alternative) sources
• meat • Fish • Eggs • Cheese • Milk •Yoghurt • Soya beans
• Meat alternatives (textured vegetable protein and mycoprotein)
What are the LBV protein foods (vegetable origin) sources?
• Peas • Nuts • Beans • Lentils • Cereals
What is the reference intake for protein?
Adults need at least 50g of protein, or approximately 0.75g for every 1kg of body weight. Children and teenagers need more because they are growing so quickly
What are the functions of protein?
• Protein is needed for the growth and repair of all body cells (skin, blood, tissues and bones)
• It produces heat and energy
• it is necessary for the production of important substances in the body eg; hormones, enzymes and antibodies (which fight disease)
What are the protein deficiency symptoms?
Protein deficiency symptoms include:
• poor or stunted growth with muscle wasting
• Slow healing of wounds
• Hair breakage and loss
• Poor general health
• Hormone and enzyme imbalances
What is the composition of fats?
Fats also called lipids can be in solid or liquid form. Liquid fats are called oils.
Fats are made up of three elements:
1. Carbon (C)
2. Hydrogen (H)
3. Oxygen (O)
Fats contain twice as much carbon as protein or carbohydrates and therefore produce twice as much energy
Each fat unit is made up of three fatty acids and one glycerol molecule
During digestion these are separated so that they can be used by the body
What is the classification of fats?
There are two types of fat:
1. Saturated fat contains cholesterol – a type of fat found in the blood. Saturated fat is generally found in foods that come from animals
2. Unsaturated fat does not contain cholesterol. It is found in foods that come from vegetable or plant sources and in oily fish
What are the sources of saturated fats?
• Butter • Cream • Cheese • Fatty meats
• Hard margarines • Pastries • Cakes
• Biscuits • Eggs • Coconut oil
What are the sources of unsaturated fats?
• Avocados • Nuts • seeds • oily fish
• Vegetable oils eg: olive oil
• Some soft margarines eg; flora
What are omega-3 fats
Omega-3 fats are a type of unsaturated fat found in oily fish, nuts and seeds. They are important for brain development and also help to lower blood cholesterol levels
What is the reference intake for fats?
An average adult should not consume more than 70g of fat per day. No more than 20g of this fat should be saturated.
No more than 30% of your daily energy intake should be from fats. It is better to get energy from carbohydrates and lean protein foods
What are the functions of fats?
• Fats produce heat and energy
• Adipose tissue (a layer of fat stored under the skin) helps to keep the body warm
• A layer of fat surrounds vital organs, such as the liver and kidneys to protect them from damage
• Fats are a source of the fat-soluble vitamins A, D, E and K
What happens with the overconsumption of fats?
There are two main health problems associated with having too much fat in the diet:
1. Obesity: Fats are all high in kilocalories. Eating too much fat causes weight gain and obesity
2. Coronary heart disease: Too much cholesterol in the blood causes it to stick to the artery walls, increasing the risk of heart attacks
How do you reduce fat in the diet?
• Limit high-fat foods such as takeaways
• Use low-fat cooking methods (eg; grilling, steaming or baking) instead of frying
• Modify recipes to reduce fat content eg: use olive oil instead of butter for frying
• Choose low-fat fresh, unprocessed meats. Trim any visible fat from meat before cooking
• Choose low-fat products eg: low-fat cheese, low-fat yoghurt
• Always read food labels to check fat content (particularly saturated fats)
What is the composition of carbohydrates?
Carbohydrates are made up of three elements:
1. Carbon (C)
2. Hydrogen (H)
3. Oxygen (O)
These elements combine to form simple sugars eg: glucose
These simple sugars link or combine together to form long chains of starch
During digestion, these long chains are broken down by enzymes into simple sugars so that they can be used by the body
What is the classification of carbohydrates?
Carbohydrates come from three different groups:
1. Sugar
2. Starch
3. Dietary fibre
What are the sources of sugar carbohydrates?
• Table sugar • Sweets • Honey • Cakes
• Soft drinks • Ketchup • Biscuits • Jam
• Fruit
What are the sources of starch carbohydrates?
• Cereals eg; wheat rice • Bread • Pasta
• Flour • Potatoes