All about nutrients

Carbohydrate

When you eat carbohydrates, your body breaks the carbohydrates down into glucose and this is what provides energy to your body. Most of the calories (energy) that your body needs should come from carbohydrates.

Carbohydrates are found in foods such as bread, potatoes, pasta and rice. Carbohydrate foods can be broken down into two categories – these are:

1. Simple carbohydrates

Simple carbohydrates are referred to as sugars. Carbohydrate foods that are high in sugars include sweets, sugary drinks, honey, fruits such as grapes, bananas and oranges, dried fruits such as raisins and some vegetables including onions, carrots and sweetcorn

2. Complex carbohydrates

Complex carbohydrates consist of starch and dietary fibre. Carbohydrate foods that are high in starches include bread, pasta, potatoes, cereals and rice. It is these types of carbohydrate that are broken down and turned into glucose in the body in order to provide energy. As these carbohydrates are used to provide energy, they are less likely to be stored as fat. The fibre provided by complex carbohydrates can be either soluble or insoluble fibre. Soluble fibre (found in fruits, nuts, seeds and brown rice) helps to lower cholesterol and control blood sugar levels. Insoluble fibre (found in wholegrain bread, vegetables, cereals and nuts) doesn’t provide any energy but it can help to improve digestive health and may even help to prevent colon cancer.

Protein

When you eat proteins, your body breaks the proteins down into amino acids. Your body needs amino acids to help with the growth and repair of muscles, blood cells, hair and other tissues. Certain amino acids can’t be made by your body, so they need to come from proteins in your diet instead.

Proteins are also a source of calories – however, they only supply energy if the body does not have enough carbohydrates or fats available.

Foods that provide a good supply of protein include:

• Meat
• Fish
• Chicken
• Eggs
• Milk and milk products
• Pulses (peas, beans and lentils)
• Nuts
• Quorn, tofu and other meat alternatives

Fat

We need fat in our diet to help maintain skin and hair, provide protection for vital organs, give our body warmth and insulation and to help us absorb vitamins.

The three main types of fat are:

1. Saturated fats

Saturated fats are found in animal products such as meat, butter, milk, cream and cheese.

2. Polyunsaturated fats

Sources of polyunsaturated fat include cooking oils (including sunflower oil), oily fish, such as salmon and mackerel, nuts and seeds.

3. Monounsaturated fats

Sources of monounsaturated fat include olive oil, avocados, nuts, olives, fatty fish (such as sardines) and rapeseed oil.

Saturated fats are known as ‘bad fats’ as they raise cholesterol levels and can increase the risk of heart disease. We should aim to reduce the amount of saturated fat in our diet. Unsaturated fats are less harmful and should be incorporated into our diet.

Vitamins

Vitamins are natural substances found in foods and they are essential in keeping your body healthy. Most vitamins cannot be made by your body, so they must be consumed through the diet. Vitamins are not a source of energy, but they are essential in:

• Helping your body to release energy from the food you eat
• Helping muscles to grow and repair
• Helping to fight illness and infections

Vitamins can be water-soluble or fat-soluble.

Water-soluble vitamins are:

• B Vitamins – These vitamins help your body to release energy from the food you eat and also support growth. Dairy products, cereals, nuts, seeds and meat are all good sources of B vitamins.
• Vitamin C – This vitamin helps your body to absorb iron from the food you eat. It is also an antioxidant, which helps to prevent harmful substances from damaging the body. Fruit and vegetables are good sources of vitamin C – especially citrus fruits and green leafy vegetables.

Fat-soluble vitamins are:

• Vitamin A – This vitamin is important for healthy eyesight, healthy skin and also for fighting infections. Liver, milk, eggs, cheese, oily fish, and orange, yellow and dark green vegetables are all good sources of vitamin A.
• Vitamin D – This vitamin helps your body to absorb calcium from the food you eat. It is also important for healthy bones and teeth. Meat, oily fish, eggs and butter are all good sources of vitamin D. We also get vitamin D when our skin is exposed to sunlight.
• Vitamin E – This vitamin is an antioxidant, so it helps to prevent harmful substances from damaging the body. Vegetable oils, nuts, seeds and green leafy vegetables are all good sources of vitamin E.
• Vitamin K – This vitamin helps your blood to clot after injury, which means you don’t lose too much blood and wounds heal more quickly. Spinach, broccoli, cheese and liver are all good sources of vitamin K.

Minerals

Minerals are chemical elements found in food and, while they are not a source of energy, they contribute to many useful body functions in order to keep you healthy. Key minerals include calcium, iron, sodium and potassium.

Calcium

We need calcium to keep teeth and bones strong, to help blood to clot after injury and to help nerves and muscles to work properly. Sources of calcium include milk and dairy products, cereals, nuts, seeds and green leafy vegetables (such as spinach).

Iron

Iron plays an important part in helping your body to produce haemoglobin (which carries oxygen in the blood around the body). Sources of iron include red meat, green leafy vegetables (such as spinach), dried fruit, cocoa, plain chocolate and egg yolk.

Sodium

We need sodium to control the amount of water in our body and to help nerves and muscles work effectively. Sources of sodium include crisps, salty or cured meats like bacon and foods that are canned in brine (salt water), such as tuna.

Potassium

We need potassium to control the amount of water in our body, to help muscles work effectively and to prevent muscle cramps. Potassium is found in many foods. Bananas and potatoes are particularly good sources of potassium.

Fibre

While some sources of information list fibre as one of the main nutrients, it cannot officially be classed as a nutrient as it is not directly used by the body the way other nutrients are. However, everyone needs a good amount of fibre in their diet as it helps to keep the digestive system healthy, prevent constipation, lower cholesterol levels and reduce the risk of bowel cancer. Fibre also makes you feel fuller and reduces your appetite.

Fibre can be either insoluble or soluble. Insoluble fibre helps to prevent constipation, as it softens stools and helps them move more easily through the bowels. Soluble fibre helps to lower cholesterol and control blood sugar levels.

Sources of insoluble fibre include:

• Wholemeal (brown) bread, pasta and rice
• High fibre breakfast cereals
• Pulses (beans, lentils, etc)
• Nuts and seeds
• Potatoes with skins left on

Sources of soluble fibre include:

• Fruits, such as bananas and apples
• Baked beans
• Chick peas
• Root vegetables, such as carrots and potatoes
• Grains, such as oats and barley

Water

Water is essential for life and it plays a very important part in helping us to stay healthy. Our body is made up of around 60% (two-thirds) water and water has many important jobs in the body – for example:

• It helps to control our body temperature. When we need to cool down (for example, during and after exercise), water leaves our body as perspiration (sweat).
• It carries nutrients around our body and helps the body to absorb nutrients.
• It helps to remove waste products from our body.
• It helps our body cells to function properly.

For these reasons, it is really important that we take in sufficient amounts of fluid each day. If we don’t get enough fluid, it can cause us to feel tired, get headaches and not perform at our best.

As you learned earlier in this Unit, the Eatwell Guide recommends that we drink 6-8 glasses/cups of water every day. However, this does not have to be water alone – it can also include juice, milk, soup and also fruits/vegetables that have a high water content (such as cucumbers, watermelons and tomatoes)…in fact, the food that we eat provides around 20% of our daily fluid intake.

It is important to remember that the more active you are, the more water your body will lose through perspiration. This will mean you may need to consume more than the recommended 6-8 glasses per day. Drinking water is enough to rehydrate the body following moderate exercise/physical activity – however, following longer periods of high intensity exercise, sports drinks that contain added sugar and sodium (salt) can be better at replacing the fluid that has been lost from the body through perspiration.