Unit 12 – Nutrition
Assignment 1 – Concepts of nutrition and digestion
Good nutrition means getting the right amount of nutrients from healthy foods in the right
combinations. Having nutrition knowledge and making smart choices about the foods you eat can
and will help you achieve optimum health over your lifetime, and be a key to avoiding obesity,
illness, and many of today’s chronic diseases.
Nutritional requirements:
Essential: Nutrients we need because our body can’t produce them.
Non-essential: Nutrients we don’t need because our body can produce them.
Macronutrients - Macronutrients are nutrients that provide calories for energy. They are
substances needed for growth, metabolism, and for other body functions. Macro means large,
therefore macronutrients are nutrients needed in large amounts. Macronutrients include;
Carbohydrates – Carbohydrates are the macronutrient that we need
in the largest amounts because they are our main source of energy.
They can be found in foods such as bread, pasta, cereals, and
potatoes, as well as sugary foods. Carbohydrates can be used for
energy straight away or stored in the liver as glycogen. Carbohydrates help the brain to
function as well as muscles to contract. Athletes in training will eat more carbohydrates, and
possibly load before an event to ensure that their bodies have a sufficient store of energy.
However, a non-athlete should be careful to not eat too many carbohydrates, as if it is unused,
it will get stored in the body as fat. In general, we should eat 260g of carbohydrates each day.
Protein – Proteins are made from amino acids. They can be
found in animal produce such as meat, fish, milk and eggs.
They can also be found in beans and lentils. Proteins are used
to help us grow and repair tissues. They are both essential and
non-essential. Our bodies can produce proteins too. Proteins are particularly important in the
recovery stage after exercise. For example, they can help repair tears in the muscle fibres to
aid muscle hypertrophy. In general, we should eat 50g of protein per day.
Fats - Fats are a constant source of energy within our body. They can
also provide warmth for our bodies, and protection for vital organs.
There are 3 types of fat. Saturated fats are usually found in animal
fats, and generally solid at room temperature, such as butter and cheese. However, too much
saturated fats in our diet can cause blockages in the arteries, and raise cholesterol, as well as
lead to obesity, type 2 diabetes, heart disease, some cancers or strokes. Monosaturated fats
have one unsaturated carbon bond. They are usually liquid at room temperature, such as oils.
They are healthier for the body than saturated fats. Polyunsaturated fats are the bets type of
fat for you. They are found in oily fish and some oils. They are useful for low impact activity
because they produce energy which is released slowly. However, if we eat too much fat, we
, consume more energy than we burn, so this is when we are likely to gain weight. In general, we
should eat 70g of fat per day, but only 20g of this should be saturated.
Fibre - Fibre is very important in our diets, as it keeps our
digestive system working properly. It slows down how fast
the stomach empties, and helps to keep the large intestine
clear. It can be found in fruit and vegetables and
wholegrains. Fruit and vegetables are particularly important as they can also lower blood
pressure and reduce the risk of developing heart disease. However, fruit contains lots of
natural sugars. They are good in moderation but having a high proportion of fruit in your diet
can rot your teeth and cause you to put on weight if it gets stored as fat. Vegetables are
potentially better than fruits in that respect, as they contain low amounts of sugar. Overall, we
should eat at least 5 portions of fruit or vegetables per day. We also need about 30g of fibre
per day.
Water - Water is also very important in our diets. It aids all chemical
reactions in the body, and helps with digestion. Water can also be used
when an individual is on a diet, as it can fill you up, causing you to eat less.
However, too much water can cause salts and electrolytes that we need to
become too diluted. We should consume 2-3 litres of water per day.
Micronutrients - Micronutrients are vitamins and minerals required in small amounts that are
essential to our health, development, and growth. Vitamins and minerals can be found in many
foods, for example, vitamin C can be found in citrus fruits, and calcium can be found in milk.
There are also manufactured vitamins and mineral forms that people can take to help get enough
of them into their diet, so that it is more balanced.
Vitamins – Vitamins allow the body to grow and develop. They also play an important part with
the body’s functions. The main vitamins that our body needs are; A, B, C, D, E, and K. For
example, vitamin C, helps to protect cells to keep them healthy, and helps with wound healing.
Minerals – Minerals are important for keeping our body strong. The main minerals needed are
calcium and iron. For example, iron is important to produce red blood cells, which carry oxygen
around the body, and calcium is important, as it keeps teeth and bones strong. If we don’t have
enough calcium in our diets, then our teeth and bones can become weak so they are vulnerable to
breaking easily.
