Chapter 5 Lesson 2 Carbohydrates proteins and Fats

Chapter 5 Lesson 2 Carbohydrates, proteins and Fats • Carbohydrates – Starches and sugars found in foods • Carbohydrates are the preferred source of energy, providing 4 calories per gram • Depending on the chemical makeup, carbohydrates are classified into 2 types – Simple or complex

Carbohydrates • Health experts recommend that 55 to 65% of your daily calories come from carbohydrates, mainly complex carbohydrates

Simple Carbohydrates • Sugars are present naturally in fruits, some vegetables, and milk • Fructose – Fruits • Lactose – Milk • Maltose – grain • Sucrose – Table sugar

Complex Carbohydrates • Starches – found in great supply in rice and other grains, seed nuts, legumes (dried peas and beans) • Tubers – (potatoes, cassava, yams, taro) • Starches are called complex carbohydrates because they are chemically more complex than simple carbohydrates • During digestion, starches break down into sugar

The Role of Carbohydrates • Before body can use carbohydrates it must be broken down into glucose • Glucose – a simple sugar and IS THE BODY’S CHIEF FUEL • Glucose not used right away is stored in the liver and muscles as a starch like substance Called GLYCOGEN

The Role of Carbohydrates • Later when glucose is needed the glycogen is converted back to glucose • When people consume more carbohydrates than their body need for energy or can store as glycogen, this excess is stored as adipose tissue or fat

Fiber • Found in the tough, stringy part of vegetables, fruits, and grains, fiber is a special for of complex carbohydrate • It cannot be digested or used for energy it helps move waste through your digestive system

Fiber • Helps reduce some types of cancer • Helps reduce constipation, appendicitis • Helps control diabetes and some types of fiber seem to help lower blood cholesterol • Increase fiber in body by eating an abundance of fruits and vegetables • Bran cereal, wheat breads, pasta, oatmeal, brown rice, popcorn • Need 25 grams of fiber per day • Special form of Complex carbohydrates

Proteins

Proteins • Nutrients that help build and maintain body tissues • Muscle, bone, skin, connective tissue, teeth, blood and vital organs all contain protein • Calories provide 4 calories per gram • Excess protein is converted to fat and stored for storage

Proteins • Proteins are made of building blocks called AMINO ACIDS • Your body can make all but 9 of the 20 amino acids • These 9 are called ESSENTIAL AMINO ACIDS because they must come form food you eat • Proteins – 2 categories – Complete and Incomplete

Complete Proteins • Complete proteins – Contain all essential amino acids that come from food you eat the body needs and in the proper amounts • These include animal products, such as fish, meat, poultry, eggs, milk, cheese, yogurt, and many soybean products

Incomplete Proteins • Foods that lack some of the essential amino acids • Such food sources come from plants: • Legumes, nuts, whole grains, and seeds • Eating various incomplete protein sources – Legumes with grains give the equivalent of a complete protein • P. 104

The Role of Proteins • During life new proteins form constantly to replace damage or worn out body cells • Proteins in enzymes, hormones and antibodies also help regulate many body processes

Fats

Fats • Fats are a type of lipid – a fatty substance that does not dissolve in water • Fats are composed of carbon, hydrogen, and oxygen atoms • Fats are made of fatty acids • Fats classified as SATURATED OR UNSATURATED

Fats • Gram for gram, fats deliver more than twice the energy of either carbohydrates or proteins

Saturated Fats • Fatty acids are called saturated when the fatty acid hold all the hydrogen atoms it can • Saturated Fats: Stay solid or semi solid at room temperature • Animal fats and tropical oils – – Palm oils Palm kernel oil Coconut oil Fats in beef, pork, egg yolks, and dairy foods

Unsaturated Fats • When fatty acid is missing one or ore pairs of hydrogen atoms • Most vegetable fats are unsaturated: Liquid at room temperature • Olive oil, canola soybean, corn, cotton seed oils are unsaturated • *Hydrogenated foods – adding missing hydrogen atoms to food - PEANUT BUTTER, MARGARINE

The Role of Fat • Fats carry vitamins A, D, E, K into your blood stream and serve as sources of linoeic acid – Essential fatty acid not made in the body but which is essential for growth and healthy skin • Body fat surrounds and protects vital organs • Protects body against excessive heat or cold

The Role of Fat • Body needs only a moderate amount of dietary fat each day • Average teenage girl: 2, 200 calories per day and 66 grams of fat per day • Average teenage boy: 2, 800 calories per day and 84 grams of fat per day • Too much fat linked to obesity, heart disease, diabetes • Fat intake no more than 30% daily

Cholesterol • Fatlike substance produced in the liver of all animals and therefore, found only in foods of animal origins – meats, poultry, fish, eggs and dairy products • Cholesterol is instrumental in production of sex hormones, vitamin D and protective sheaths around nerve fibers