Nutrition Flashcards
What are nutrients?
Nutrients are substances the body needs for energy, building materials, and control of body processes.
Which nutrients are needed in relatively high amounts?
Carbohydrates, åroteins, lipids, and water are nutrients needed in relatively large amounts.
What nutrients are needed in smaller amounts?
Vitamins and minerals are nutrients needed in much smalæler amounts.
What is an adequate diet?
An adequate diet provides energy for the performance of metabolic work, although the energy could be in any form.
What is a balanced diet?
A balanced diet provides all dietary requirements in the correct proportions. Ideally this would be 1/7 fat, 1/7 protein and 5/7 carbohydrate.
Undernutrition vs malnutrition
In conditions of undernutrition, the first concern is usually provision of an adequate diet, but to avoid symptoms of malnutrition, a balanced diet must be provided.
What should a balanced diet contain?
A balanced diet should contain the correct proportions of carbohydrates, lipids, proteins, vitamins and minerals, water, and dietary fibre.
Good sources of carbohydrates
Rice, potatoes, wheat and other cereals provide starch. Food sweetenings, sweets, and soft drinks, and preservatives provide refined sugar, such as sucrose and glucose.
Functions of carbohydrates in humans
A source of energy. Excess carbohydrate can be stored as glycogen and as fat.
What are carbohydrates absorbed as?
Carbohydrates are digested in the mouth and absorbed as glucose.
How are refined sugars absorbed?
Refined sugars are absorbed very rapidly, giving a sudden boost of energy source.
How is starch digested?
Starch is digested and absorbed more slowly, giving a steady supply of energy source: starches are called slow release carbohydrates.
Sources of lipids
Meat and animal foods are rich in saturated fats and cholesterol. Plant sources such as sunflower seeds and peanuts are rich in unsaturated fats.
Functions of lipids in humans
Fats and oils are an important source of energy. They are especially valuable as energy store because they are insoluble in water. They also provide insulation.
How are fats and oils digested?
Fats and oils are digested in the small intestine and absorbed as fatty acids and glycerol.
What are the two acids that lipids can contain?
Some lipids contain saturated fatty acids, and others contain unsaturated fatty acids.
How much fat can the body store?
The body can store unlimited amounts of fat, contributing to obesity.
What can cause diseases of the circulation?
The incorrect balance of saturated and unsaturated fatty acids, or an excess of cholestrol, can cause diseases of the circulation.
What are good sources for proteins?
Meat, fish, eggs from animals, and legumes and pulses from plants.
What are the two substitues for meat?
The soya bean is one of the best sources of protein and contains very little fat. Soya beans can be flavoured and textured to make them taste and feel like meat. Mycoprotein is also a low-fat substitue for meat.
What are the 5 main functions of proteins in humans?
Many functions including
-catalysts (enzymes)
-transport molecules (like haemoglobin)
-structural materials, as in muscles
-hormones, such as insulin
-in defence against disease, as antibodies
Where are proteins digested?
Proteins are digested in the stomach and small intestine and absorbed as amino acids.
How many different amino acids make up all the proteins in the human body?
20 different amino acids are needed to make up all of the different proteins in the human body.
Essential amino acids
Some of these amino acids must be supplied because the body cannot make them. These are the essential amino acids.
Amino acids in animals vs plants sources
Proteins from animal sources usually contain all 20 amino acids but plant sources often lack one or two of the essential amino acids.
What can deficiency of protein called?
Deficiency of protein causes, poor growth, in extreme cases may cause marasmus kwashiorkor. 
