Dietary Fibre, Water & Energy

What is Energy?  Energy gives us the ability to do EVERYTHING  The amount of energy that Different people require Varies from day to day and Due to different factors: Age, Activity level, state of health, gender Energy From Food As a store of energy. E.g. fat stores To produce heat to keep us warm To make electrical energy so nerves send messages To produce sound so we can talk To make chemical reactions happen To enable us to move

Factors  Age Babies and children need a lot of energy because they are very active and continuously growing. Teenagers need a lot more energy than adults because they are still growing and usually active. As people get over, the bodies energy requirements get less as the body slows down.  Activity levels The more active you are the more energy you need. Some activities need more energy to sustain energy levels throughout the day so energy dense foods are needed.  State of health Sometimes illness can increase energy levels as your body fights infection. When you are ill you may loose your appetite so people may find that they loose weight when they are ill as your body has to rely on fat stores. When a woman is pregnant or lactating her energy levels increase to cope with the demands of the growing baby.  Gender On average males need more energy each day than women because they are generally bigger and have more muscles. However everyone has individual needs for energy so a tall, physically active female will use more energy than a short, non active male!

Energy and how it is measured  All energy comes from the sun, plants trap the sun’s energy and store it as carbohydrate or fat. Animals eat the plants and use some of the energy to be active and store some of it as fat. People eat animals and plant sourced food and use the energy found in the macronutrients they contain (carbohydrates, fat and protein)  Energy is measured in 2 ways: Metric measurement – joules. Joules are very small measurements so for measuring energy in food we use the kilojoule.  We also use another measurement caller the calorie (cal) One calorie is a very small measurement, so for measuring energy in food we use the kilocalorie(Kcal)  1 kj = 1,000j  1 kcal = 1,000cal  1 kcal = 4.2kj

Sources of Energy  Our bodies prefer carbohydrate as our main source of energy. During digestion, the carbohydrate is broken down into individual glucose molecules. Glucose travels around the bloodstream to all the body cells to provide energy.  What other nutrients provide energy?

Getting the balance right.  Most of the energy we need every day comes from the food we eat.  We need more energy for any physical activity that we do – walking, standing, nodding our head, talking or picking up a bag.  If we take in the same amount of energy every day and use the same amount of energy every day our weight will maintain. However if we increase the amount of energy rich foods we eat, or reduce the amount of physical activity we do, our weight will increase.

Water – why do we need it?  Water isn’t a nutrient but it is very important in our diet!  Our bodies are made up of 60% water, it is found in all cells and tissues, it is part of most chemical reactions in the body. It is found in all body fluids: blood, saliva, digestive juices, sweat, urine and fluid in our joints. It regulates our body temperature and helps get rid of waste products from the body as urine and faeces. It keeps the linings of the digestive system, mucous membranes and the lungs moist and healthy. It helps keep the concentration of substances in the blood and helps provide the skin drying out.  Recommended amounts of water intake is 1.75 – 2 litres per day  UK water supplies have been treated to make the water safe for us to drink, we can get water from some foods too such as fruits and vegetables.  If we don’t have enough water, we become dehydrated with symptoms such as: headaches, dark concentrated urine, weakness, nausea, weakness, overheating of the body, confusion, sunken eyes, changes in blood pressure, rapid heart beat or loose, wrinkled skin.  If we have too much water it is called, water intoxication, if you drink too much water, eventually the kidneys will not be able to work fast enough to remove it from the body and the blood becomes diluted. This can cause the brain to swell, headaches, nausea, muscle twitching, convulsions and even death.

Fibre – why do we need it?  Fibre is the name of a group of natural plant materials that our bodies cannot digest. Fibre has different names that people call it: roughage, dietary fibre, fibre but its scientific name is non starch polysaccharide (NSP)  Fibre is made up of Cellulose – found in stems, leaves, leaf stalks, the outside layers of seeds and beans and the peel on fruits and vegetables. Pectin – this is found in fruits such as plums, apples and blackcurrants ad it is the substance that makes jam set.  The body needs fibre to pass solid waste matter (faeces) it does this by making them soft and bulky so they can move through the intestines which helps the intestines stay healthy and work properly. Fibre makes you feel full after meals so we are less likely to eat more food between meals which also helps to reduce the amount of cholesterol in the blood.  The connection of water and fibre is that the water helps to bulk out the faeces allowing it to pass more easily.  If we don’t have enough fibre in our diet we end up with constipation, this is when the faeces don’t bulk out and stop flowing through the intestines.  In people who are often constipated, people fid it difficult to get rid of faeces and the lining of the intestines become irritated and damaged which can lead to a disease called diverticular disease or diverticulitis  A diet low in fibre can increase the risk of developing cancer in the intestines especially the bowel.