We are what we eat Anna Drabczyńska Magdalena Banaszek 2007
A BALANCED DIET A balanced diet must contain: • carbohydrates • protein • fats • vitamins • mineral salts • fibre It must contain these things in the correct proportions
Nutrients • Carbohydrates: these provide a source of energy. • Proteins: these provide a source of materials for growth and repair. • Fats: these provide a source of energy and contain fat soluble vitamins. • Vitamins: these are required in very small quantities to keep you healthy. • Mineral Salts: these are required for healthy teeth, bones, muscles etc… • Fibre: this is required to help your intestines function correctly; it is not digested.
Carbohydrates Carbohydrates are broken down into glucose to provide fast-release energy. • Carbohydrates are the most important source of energy. They contain the elements of Carbon, Hydrogen and Oxygen. • We obtain most of our carbohydrates in the form of starch. This is found in potatoes, rice, spaghetti, yams, bread and cereals. Our digestive system turns all this starch into another carbohydrate called glucose. Glucose is carried around the body in the blood and is used by our tissues as a source of energy.
Proteins Proteins provide the „fabric” for all the soft tissues of the body: skin, muscles and organs.They are therefore vital for the growth and repair. • Proteins contain Carbon, Hydrogen, Oxygen, Nitrogen and sometimes Sulphur. • Proteins are very large molecules, so they cannot get directly into our blood; they must be turned into amino-acids by the digestive system. There are over 20 different amino-acids. • Proteins can also be used as a source of energy.
Fats • Fats are used as a source of energy (slow relese energy); they are also stored under the skin helping to insulate us against the cold. • Do not think that by avoiding fat in your diet you will stay thin. If you eat too much carbohydrates, you will convert some of them into fat, so you will put on weight. • Remember, you must have some fat in your diet because it contains fat soluble vitamins – A, D, E and K.
Vitamins • Vitamins are only required in very small quantities. • Vitamin A: keeps the skin healthy and maintains good eyesight and night vision. • Vitamin C: needed for your body to repair itself, keeps the skin and gums healthy, helps heal wounds more quickly. • Vitamin D: keeps the bones and teeth strong, prevents rickets, and help the body absorb calcium.
Mineral salts These are also needed in small quantities, but we need more of these than we need of vitamins. • Iron: required to make haemoglobin. • Calcium: required for healthy teeth, bones and muscles. • Sodium: all cells need this, especially nerve cells. • Iodine: used to make a hormone called thyroxin.
Fibre • We do not digest cellulose. • This is a carbohydrate used by plants to make their cell walls. It is also called roughage. If you do not eat food materials which contain fibre you might end up with problems of the colon and rectum. • The muscles of your digestive system mix food with the digestive juices and push food along the intestines by peristalsis; if there is no fibre in your diet these movements cannot work properly
A balanced diet • You must have carbohydrates, protein, fats, vitamins, mineral salts and fibre in the correct proportions. • If there is not enough protein, you will not be able to grow properly and you will not be able to repair yourself i.e. wounds will not heal properly. • If you do not have enough energy containing foods you will feel very tired, you will not have enough energy. • If you have too much energy containing foods you will become overweight. • If you think that you are overweight you might try taking more exercise to "burn off" some of the excess food which you ate at you last meal.
Food Guide Pyramid - 1 The Food Guide Pyramid is one way for people to understand how to eat healthy. A rainbow of coloured, vertical stripes represents the five food groups plus fats and oils. Here's what the colors stand for: orange - grains green - vegetables red - fruits yellow - fats and oils blue - milk and dairy products purple - meat, beans, fish, and nuts
How is Energy Measured? • Energy is mesured in kilojoules (kJ) or kilocalories (kcal). • Examples: • Cereal – 364 kcal per 100g • Sugar - 400 kcal per 100g • Jam - 132 kcal per 100g • Rice - 148 kcal per 100g • Fish - 253 kcal per 100g
Total Energy Needed The total amount of energy needed is easy to workout: Total Basal Working Energy = Metabolic + Energy Needed Rate (BMR) Basal Metabolic Rate – This is the energy you need to stay alive, awake and warm, while at rest. Working Energy – This is extra energy you need to perform all other activities, e.g. move, digest food, exercise, etc.
Do We All Need the Same Amount of Energy? We do not all need the same amount of energy (calories): it depends upon a number of other factors: Age Young people require much greater level of energy to ensure they grow normaly, for example: - A young child needs 1600 - A teenager needs 2300 to to 2100 calories per day. 2800 calories per day. - An adult male needs 2600 - An adult female needs 1800 to 3500 calories per day. to 2500 calories per day.
Sport & Exercise If a person undertakes regular exercise, they will need more energy (calories). For example: • 1 hour of swimming uses about 360 calories • 1 hour of running uses about 600 calories • 1 hour of gardening uses about 300 calories • 1 hour of cycling uses about 330 calories • 1 hour of walking uses about 100 calories
Body Mass Index • Your BMI is calculated by dividing your weight in kilograms by your height in metres squared. The result you get is then classified into the following groups • Recommended BMI Chart • Underweight - BMI less than 18.5 • Ideal - BMI 18.5-25 • Overweight - BMI 25-30 • Obese - BMI 30-40 • Very obese - BMI greater than 40
A BMI • A BMI measurement is not as accurate if you're an athlete or very muscular (muscle weighs more than fat) as this can push you into a higher BMI category even if you have a healthy level of body fat. It's also not accurate for women who are pregnant or breastfeeding, or people who are frail.