Food and Energy Section 1

Why You Need Food Food provides your body with materials for growing and for repairing tissues. Food also provides energy for everything you do. Nutrients are the substances in food that provide raw materials and energy the body needs to carry out all its essential processes. There are 6 groups of nutrients necessary for human health: Carbohydrates - Proteins Fats - Vitamins Minerals - Water

Energy When nutrients are used by the body for energy, the amount of energy they release can be measured in units called calories. One calorie is the amount of energy needed to raise the temperature of one gram of water by one degree Celsius. One calorie is the same as 1 kilocalorie (kcal) or 1,000 calories. For example, one serving of popcorn may contain 60 Calories (60 kcal) or 60,000 calories of energy. The more calories a food has, the more energy it contains.

Carbohydrates Carbohydrate are composed of carbon, oxygen, and hydrogen. One gram of carbohydrate provides your body with 4 calories of energy. Carbohydrates provide the raw materials to make cell parts. Simple Carbohydrates: Also known as sugars. One sugar, Glucose, is the major source of energy for yours body’s cells. Your body converts other types of sugar into glucose. Complex Carbohydrates: They are made up of many sugar molecules linked together in a chain. Starch is a complex carb. found in rice, wheat, corn, potatoes, etc. Your body breaks starch down into individual sugar molecules before it releases the energy. Fiber is a complex carb that cannot be broken down into sugars.

Fats Fats are energy-containing nutrients that are composed of carbon, oxygen, and hydrogen. One gram of fat provides your body with nine calories of energy. Fats form part of the cell membrane Fat tissue protects and supports your internal organs and insulates your body. Saturated Fat: are usually solid at room temperature. Meat and dairy products contain large amounts of saturated fats. Unsaturated Fats: are liquids usually at room temperature. Most cooking oils are unsaturated fats. Trans Fat: when hydrogen is added to vegetable oils. Companies use this to allow foods like chips and margarine to stay fresh longer. Saturated fats and trans fat are not healthy.

Fats Contd. Cholesterol: a waxy, fatlike substance found only in animal products. Your liver makes cholesterol, so any added cholesterol is unnecessary. Nutritionists recommend that no more than 30% of your diet contain fats. A diet high in fat and cholesterol can lead to a buildup of fatty material in the blood vessels and cause heart disease.

Proteins Proteins are nutrients that contain nitrogen as well as carbon, hydrogen, and oxygen. Proteins are needed for tissue growth and repair. They play an important part in chemical reactions within cells. About 10 – 35 percent of your daily Calorie intake should come from proteins. Amino Acids: Small units that make up proteins and are linked together chemically to form large protein molecules. Thousands of proteins are built from about 20 amino acids. Your body can produce about half of them itself, the rest come from the foods we eat.

Vitamins and Minerals Vitamins act as helper molecules in a variety of chemical reactions in the body. Most vitamins are obtained through foods. Fat- Soluble Vitamins: dissolve in fat and they are stored in fatty tissues in the body. Vitamins A,D,E AND K are fat-soluble. Water- Soluble: vitamins dissolve in water and are not stored in the body. Vitamin C and Vitamin B. Minerals: Nutrients that are not made by living things. Minerals are absorbed in plants through soil. Vitamins and Minerals are essential to carry out numerous processes.

Water Water is the most important nutrient because it carries out the body's vital processes, such as chemical reactions that breakdown nutrients. 65% of your body is made of water Under normal conditions, your body needs 2 liters of water every day. Water is needed to create perspiration and carry out the homeostasis process. Water makes up blood.